The inner, hilltop polygonal-walled circuit at ancient Aletrium (modern Alatri,
Lazio), distinct from the town's larger outer circuit. This curated record keeps
the monument separate from the broader ancient-place authority record and models
Giulio Magli's published archaeoastronomical interpretation as an explicitly
interpretive evidence set: a proposed foundation point O to north-east-corner
summer-solstice-sunrise line, and a plan-shape correspondence with Gemini.

The early-12th-century Khmer temple-mountain of Angkor Wat (Cambodia) — a
three-dimensional model of the Hindu cosmos, its central quincunx of towers standing
for Mount Meru and its moat for the cosmic ocean. It carries a genuine, peer-reviewed
solar alignment (equinox sunrise over the central tower; a solstice sightline to
Phnom Bok) and a much-discussed claim that its measurements encode the yuga time-cycles
— the latter a striking but interpretation-dependent reading to flag.

The great 9th-century Mahayana Buddhist monument of Central Java: a stone
**mandala** built as a stepped pyramid of terraces crowned by a central stupa.
Unlike the other sites in this batch, Borobudur's mathematical interest is not
horizon astronomy but **sacred number and geometry** — its nine platforms, its 72
perforated stupas, its 504 Buddha statues, and its structure as a three-dimensional
map of the Buddhist cosmos climbing from the world of desire to the formless realm.
The central stupa reads as an axis mundi / Mount Meru. This node anchors the
`mandala`, `stupa`, and cosmic-mountain concepts and several sacred-number edges.

Cahokia, the largest pre-Columbian city north of Mexico (Mississippian culture, near
modern St. Louis, c. 1050–1200 CE), and its "Woodhenge" — a series of large timber post
circles whose perimeter posts mark the solstice and equinox sunrises against Monks Mound.
A solid North American archaeoastronomy node, closing the Mississippian gap and anchoring
the New-World solar-calendar thread alongside Chankillo and Teotihuacan.

The Neolithic standing-stone complex of Calanais on the Isle of Lewis (Outer Hebrides,
Scotland), c. 2900–2600 BCE — a cross-shaped arrangement of a stone ring, a central
monolith, and radiating rows/avenue. Its celebrated feature is a **lunar** one: at the
major lunar standstill (every ~18.6 years) the low Moon skims along the southern hills
and, from the site, appears to rise out of and set into the land. A key node for the
lunar (as opposed to solar) thread of megalithic astronomy — and one where the careful
scholarship (Ruggles) matters.

The Carnac stones in Brittany — thousands of Neolithic standing stones set in long parallel
rows (alignments) over several kilometres, c. 4500–3300 BCE. The largest megalithic
alignment complex in the world, it is a genuine wonder whose *astronomical* purpose is
much-debated: it is the type-site for Alexander Thom's contested claims of precise megalithic
lunar observatories and a "megalithic yard." A good curation node — spectacular monument,
uncertain astronomy.

The Ancestral Puebloan center of Chaco Canyon (New Mexico, c. 850–1150 CE), whose
great houses show solar and lunar building orientations, and whose Fajada Butte "Sun
Dagger" — slabs of rock that cast blades of light across spiral petroglyphs — marks
the solstices and equinoxes. It is a strong North American archaeoastronomy node,
peer-reviewed at discovery, and a good curation case because the original claims later
drew careful scholarly reassessment.

A 4th-century-BCE ceremonial complex in the Casma Valley on the north coast of
Peru whose "Thirteen Towers" form a toothed artificial horizon. Observed from two
purpose-built points, the rising and setting sun moves along the line of towers
across the year, spanning the full arc between the June and December solstices —
making Chankillo the earliest **securely demonstrated** solar-horizon observatory
in the Americas. It is the "cleanest" site node in this corpus: the astronomical
function rests on a peer-reviewed *Science* paper, not on esoteric reconstruction.

The stepped pyramid of Kukulcán ("El Castillo") at the Maya city of Chichén Itzá,
Yucatán. Its architecture encodes the solar year in stone — **365 steps** (4 × 91 +
the top platform) and 9 terraces — a secure structural fact. It is also the site of
the famous equinox "descent of Kukulcán," where light-and-shadow triangles on the
balustrade join a carved serpent head; that hierophany is real but its *deliberate
design* is genuinely debated among archaeoastronomers. This node keeps the calendar
counts as fact and treats the serpent effect with the caution the literature requires.

The Panhellenic sanctuary of Apollo at Delphi, Greece — home of the famous oracle and,
for the Greeks, the *omphalos*, the "navel of the world": a stone marking the centre of
the earth. Delphi is the corpus's clearest classical instance of the `axis mundi` /
sacred-centre concept, expressed not as a cosmic mountain or tree but as a world-navel
stone, with a charming aetiological myth to match.

A Neolithic passage tomb on the island of Gavrinis in the Gulf of Morbihan, Brittany
(c. 3500 BCE), celebrated for the most densely carved megalithic art in Europe — its
passage slabs are covered edge-to-edge with engraved spirals, arcs, chevrons and axe
motifs. Its south-easterly passage carries a winter-solstice-season solar orientation.
A key node for the corpus's `spiral` symbol thread and for megalithic art as sacred
geometry.

The Old Kingdom necropolis on the Giza plateau — the pyramids of Khufu, Khafre and
Menkaure — is the canonical test case for separating **secure** mathematical facts
(near-perfect cardinal orientation; a base-to-height ratio close to 2π) from the
huge body of **fringe "pyramidology"** (golden-ratio mysticism, the Orion
Correlation Theory, "the pyramid encodes the speed of light"). This node records
only the defensible claims and explicitly quarantines the rest — Giza is where the
curation rule earns its keep.

A Neolithic circular enclosure ("roundel," German *Kreisgrabenanlage*) at Goseck in
Saxony-Anhalt, Germany, built c. 4900 BCE — among the oldest constructions in the world
with a plausible solar function. Its two southern gateways frame the winter-solstice
sunrise and sunset, and it belongs to a wider central-European family of several hundred
early-Neolithic roundels. A good, sober "very early solar enclosure" node — with the
"oldest observatory in the world" hype held in check.

The Jantar Mantar in Jaipur — a collection of nineteen monumental masonry astronomical
instruments built by Maharaja Sawai Jai Singh II in 1734, including the world's largest
stone sundial. It is the corpus's node for *royal, scientific* astronomy in early-modern
India: not a prehistoric alignment but precision naked-eye instruments in stone, built to
measure time and celestial positions and to reconcile the astronomical traditions Jai Singh
had studied.

The vast temple precinct of Amun-Ra at Thebes (modern Luxor), built and rebuilt
across the Middle and New Kingdoms. Its principal axis runs toward the horizon
point of **midwinter sunrise / midsummer sunset**; a "high room of the sun" in the
Festival Hall of Thutmose III was arranged to catch the winter-solstice sunrise.
The solstitial orientation was first proposed by the astronomer Norman Lockyer in
1894 (with the wrong target and an over-precise date) and then put on solid footing
by the systematic temple-orientation survey of Shaltout and Belmonte (2005). This
node records the alignment via the modern peer-reviewed survey, not via Lockyer's
Victorian "astro-archaeology."

The 13th-century Sun Temple at Konark, Odisha — conceived as the colossal stone chariot of
the sun-god Surya, drawn by seven horses on twenty-four great carved wheels. Its architecture
is an explicit calendar in stone: the wheels double as sundials, the seven horses evoke the
seven days (or the seven horses of Surya's chariot), and the twenty-four wheels the fortnights
of the year. A superb node tying Indian solar theology to the numbers 7, 12, and 24.

The Neolithic chambered cairn of Maeshowe on Orkney, Scotland (c. 2800 BCE) — a
masterwork of drystone architecture whose entrance passage is aligned so that, for the
weeks around the winter solstice, the setting Sun shines down the passage and
illuminates the rear wall of the central chamber. A northern, sunset counterpart to
Newgrange's solstice-sunrise roofbox, and part of the Heart of Neolithic Orkney.

The Neolithic megalithic temple complex of Mnajdra on Malta (c. 3600–2500 BCE) —
older than the Giza pyramids and Stonehenge's sarsens — whose lower ("South") temple
is aligned so that the equinox sunrise shines straight down the central axis and the
solstice sunrises strike the edges of the doorway's flanking stones. One of the
best-preserved and best-documented solar alignments of the western-Mediterranean
Neolithic.

Mount Kailash, a striking isolated peak in western Tibet, is the corpus's clearest
*natural* cosmic mountain — identified with the mythic Mount Meru, the axis of the
world, and held sacred across four religions (Hinduism, Buddhism, Jainism, and Bön). Four
great Asian rivers rise from its region, reinforcing its role as the source-point and
centre of the world. It grounds the `cosmic mountain` and `axis mundi` concepts in a real
mountain that has never been climbed out of reverence.

A Late-Neolithic ceremonial complex in the Nubian Desert of southern Egypt,
associated with a cattle-herding society that predates dynastic Egypt. Its small
stone "Calendar Circle" was interpreted by its excavators (Malville, Wendorf and
colleagues, *Nature* 1998) as containing solstitial and possibly stellar
sightlines — which, if correct, would make it one of the world's oldest known
astronomical arrangements. It is included here as a deliberate **contested** node:
the megaliths are real and important, but the *astronomical* reading is genuinely
debated, and the corpus should carry that uncertainty explicitly rather than repeat
the "oldest astronomical site on Earth" headline.

A megalithic pillar site in north-western Kenya (near Lake Turkana), famous as the
first claimed archaeoastronomical evidence in sub-Saharan Africa: Lynch and Robbins
(1978) argued that an alignment of basalt pillars targets stars used in an East African
(Cushitic) calendar. The claim is genuinely peer-reviewed **and** genuinely contested —
which is exactly why it belongs here: a model case of how to record a disputed
archaeoastronomy claim honestly.

The Nazca lines — vast geoglyphs (straight lines, geometric figures, and animal designs)
etched into the desert of southern Peru by the Nazca culture (c. 500 BCE–500 CE). They are
included here as a **curation case**: the once-popular claim that they form an "astronomical
calendar" (Maria Reiche) was tested and largely *rejected*; current scholarship reads them as
ritual pathways bound up with water and fertility, not a sky-map. A caution against reading
astronomy into every ancient ground-marking.

A large Neolithic passage tomb in the Boyne Valley, Ireland (the Brú na Bóinne
complex), built c. 3200 BCE — older than the Giza pyramids and Stonehenge's sarsen
circle. Its defining astronomical feature is the **winter-solstice roofbox**: for a
few mornings around 21 December, sunrise light passes through a purpose-built
aperture above the entrance and runs the length of the passage to illuminate the
inner chamber. The alignment is directly observed and well documented, making
Newgrange one of the most secure solar-alignment claims in Neolithic Europe. Its
carved **triple spiral (triskele)** ties this node to the number 3 and to the
symbol corpus.

The Late-Neolithic / Early-Bronze-Age monument on Salisbury Plain, Wiltshire. Its
**one securely demonstrated** astronomical property is the solstitial axis: the
principal axis of the sarsen monument and the Avenue frames midsummer-sunrise /
midwinter-sunset. Beyond that lies a large contested literature — the "Stonehenge
as eclipse computer" claims of the 1960s — which sober archaeoastronomy has
largely set aside. This node keeps the solstice axis as fact and the lunar/eclipse
machinery as flagged, disputed material.

A late-Neolithic rammed-earth structure at the Taosi site in Shanxi Province, north
China (c. 2100 BCE) — interpreted as an astronomical observatory in which sunrise was
watched through a fan of slots between pillars to mark the seasons. If the reading holds
(it is debated), it is the oldest known observatory in China and a key East-Asian node,
tying the corpus's solar-calendar thread to the origins of the Chinese calendar.

The Circular Mound Altar (Yuánqiū) of Beijing's Temple of Heaven — the open, tiered
marble platform where Ming and Qing emperors performed the winter-solstice sacrifice to
Heaven. It is a rare case where sacred number is *explicitly* built into ritual
architecture: its stones are laid in rings of nine and multiples of nine, embodying the
Chinese cosmology of nine as the supreme *yang* number and of round-Heaven / square-
Earth. A clean, well-documented number-9 and cosmology node.

The great planned city of Teotihuacan (central Mexico, c. 100 BCE–550 CE), whose grid
is skewed a deliberate ~15.5° east of north — an orientation tied to the setting Sun on
particular calendar dates and, via a pair of "pecked-cross" markers, to the Pleiades.
Its urban layout is one of the best cases of an entire city ordered by astronomy and a
262-unit measuring module, and it anchors the pre-Maya Mesoamerican thread of this
corpus.

The Andean ceremonial center of Tiwanaku (Bolivia, near Lake Titicaca; c. 500–1000 CE),
whose Kalasasaya enclosure has solstice/equinox horizon alignments and whose famous
Gate of the Sun bears a carved frieze often read as a solar/calendar image. It is
included partly as a curation case: the site's genuine archaeoastronomy is entangled
with **Arthur Posnansky's discredited claim** that Tiwanaku is ~17,000 years old —
a textbook example of pseudo-archaeoastronomy that the corpus must explicitly reject.

The Maya city of Uaxactun (Petén, Guatemala) gave its name to the "E-Group" — an
architectural assemblage (a western pyramid facing a long eastern platform bearing three
temples) at which, from the pyramid, the sun was seen to rise over the three temples at the
solstices and equinoxes. E-Groups are the classic Maya solar-horizon arrangement; Uaxactun is
the type-site, with the important caveat that how precisely E-Groups worked as observatories
is now debated.

An egg-shaped Aboriginal stone arrangement in Victoria, Australia, built by the Wathaurong
people, whose stones appear to mark the setting sun at the solstices and equinoxes. Peer-
reviewed analysis found the solar alignments statistically unlikely to be chance — making
Wurdi Youang the corpus's Australian node and an important reminder that sophisticated
sky-knowledge is not confined to monument-building agricultural states.