Stonehenge: A 1,500-Year Construction Sequence

Stonehenge (Wiltshire, England) was built in multiple phases over ~1,500 years, not as a single project:

Phase 1: Earthwork Enclosure (~3000 BCE)

Circular ditch (~110 m diameter) with inner/outer banks, dug with antler picks. Aubrey Holes (56 pits) held timber posts or bluestones. Cremation cemetery—earliest known in Britain.

Phase 2: Timber Structures (~2900–2600 BCE)

Postholes indicate wooden settings (possibly roofed) within the enclosure. Purpose unclear—ritual, feasting, excarnation?

Phase 3: Stone Monument (~2600–1600 BCE)

• Bluestones (~2600 BCE): ~80 stones (2–4 tons) from Preseli Hills, Wales (240 km). Transport: water/land/ice debated. Set in double arc (Q/R holes).
• Sarsens (~2500 BCE): 30+ massive silcrete blocks (25–50 tons) from Marlborough Downs (32 km). Shaped with stone hammers; mortise-and-tenon, tongue-and-groove joints. Erected as trilithon horseshoe (5 trilithons) + outer circle (30 uprights + lintels).
• Bluestone rearrangement (~2200 BCE): Moved to current circle + horseshoe inside sarsens.
• Final tweaks (~1600 BCE): Y/Z holes dug (unused). Avenue extended to River Avon.

Dating & Purpose

Radiocarbon, OSL, and Bayesian modeling confirm sequence. Ceremonial/burial/astronomical functions—aligned to summer solstice sunrise, winter solstice sunset. Not a Druid temple (Iron Age, much later).

Modern stones re-erected (1901, 1919–20, 1950s–60s) where fallen; original positions documented.