← All Lesson Plans
Lesson Plan

The Stones

1923 to the present • In 2024 a team led by the geologist Anthony Clarke tested that assumption by fingerprinting the Altar Stone, not by appearance but by the radiometric ages of zircon, rutile and apatite grains locked inside it. The signature did not match Wales: it matched the Old Red Sandstone of the Orcadian Basin in northeast Scotland, more than 750 km away, with the stone probably transported in part by sea, the longest known journey of any stone in any Neolithic monument; it was likely placed around 2620 to 2480 BC, and follow-up work in 2025-26 has continued to narrow the precise source and debate the route. The finding rewrites the picture of Neolithic Britain: moving a six-tonne stone the length of the island implies not scattered, isolated farmers but a society laced by long-distance contact, seafaring, shared purpose and organisation capable of coordinating a project across the whole country without writing, metal tools or the everyday wheel. More broadly it is a lesson in how badly we underestimate the deep past: the instinct that assumed the nearest plausible source is the same instinct that imagines prehistoric people as simpler than they were, and it keeps being wrong. •
Before using this lesson plan: Read the full story or listen to the 3-minute narration (works as a bell-ringer).
Quick Use (jump to the section you need)
Discussion questions

Lesson plan: Where Stonehenge's Stones Came From

A classroom companion to the Time Rhymes story of sourcing Stonehenge's stones, from Herbert Thomas's 1923 Welsh bluestones to the 2024 finding that the Altar Stone came from northeast Scotland.

Suitable for: secondary geography, geology and history (ages 14 and up). Time: one 50 to 60 minute lesson.

Learning objectives

By the end, students should be able to:

  1. Distinguish Stonehenge's sarsens from its bluestones and the Altar Stone.
  1. Explain how geologists match a stone to its source ('provenancing'), from Thomas's 1923 mineral matching to modern grain-age fingerprinting.
  1. State where each group of stones came from and the distances involved.
  1. Explain why the Scottish origin of the Altar Stone changes how we picture Neolithic Britain.
  1. Reflect on the bias toward assuming the 'nearest plausible' explanation.

Key concepts

  • Provenance: determining where a material originally came from.
  • Sarsens, bluestones, Altar Stone: the three components and their sources (West Woods ~25 km; Preseli, Wales ~225 km; northeast Scotland ~750 km).
  • Mineral fingerprinting: matching rock by composition (1923) and by the radiometric ages of zircon, rutile and apatite grains (2024).
  • Neolithic: the late stone age farming era, here around 2600 BC, before metal tools, writing, or everyday wheeled transport.
  • Long-distance transport and exchange: what moving a six-tonne stone 750 km implies about society.

Lesson flow

  1. Hook (5 min): the question that ran for a century, not why but how the stones got there.
  1. The 1923 breakthrough (10 min): Thomas matching bluestones to Preseli, and the bold claim of human transport across southern Britain.
  1. Filling in the map (10 min): the 2020 sarsen sourcing to West Woods, and the assumption that the Altar Stone was Welsh too.
  1. The 2024 surprise (12 min): grain-age fingerprinting and the Orcadian Basin result, 750 km, probably by sea.
  1. What it means (13 min): a connected, organised, seafaring Neolithic Britain; coordinating a project the length of an island without writing, metal or the wheel.
  1. The bias lesson (10 min): why we keep assuming the nearest source, and how testing overturns it.

Discussion questions

  • Thomas's claim was doubted for decades. What evidence finally made human transport over 200 km credible, and why is extraordinary evidence demanded for extraordinary claims?
  • Moving a stone 750 km, probably by sea, with no metal tools or writing, what skills and social organisation does that require?
  • We assumed the Altar Stone was local until tested. Where else might 'nearest plausible source' thinking be leading us astray about the past?

Quick activity

Give students the three distances (about 25 km, 225 km, 750 km) and have them sketch them on an outline map of Britain, then estimate, with a chosen method (sledge, river, sea), how long each move might take a Neolithic community, and discuss what could justify the effort for the farthest stone.

Glossary

  • Provenancing: identifying the geographic source of a material.
  • Sarsen: a hard local sandstone block (the large uprights).
  • Bluestone: the smaller Stonehenge stones, sourced to Wales.
  • Altar Stone: the recumbent central sandstone slab, sourced to Scotland.
  • Zircon / rutile: durable minerals whose radiometric ages fingerprint a rock's origin.
  • Neolithic: the late stone age, here around 2600 BC.

About Time Rhymes Lesson Plans: Every lesson plan is generated alongside the story and aligned with the C3 Framework for Social Studies. The story itself is independently fact-checked with a full evidence manifest. All materials are free to use in the classroom.

Questions or suggestions? daily@timerhymes.com