trilithon
/traɪˈlɪθɑn/
noun
- A prehistoric monument made of two large upright stones with a third stone placed horizontally on top, forming a structure like a doorway; a single unit of a larger megalithic arrangement.
- The largest trilithon weighs more than 40 tons.
- Historians debate how ancient people moved the stones for each trilithon.
- Each trilithon at Stonehenge was carefully aligned with the sunrise.