A 26,000-year monument hidden at Hoover Dam

Monument Plaza at Hoover Dam features something most visitors walk right over without noticing: a terrazzo floor designed as a celestial map marking the dam's 1936 completion using Earth's axial precession — a 25,772-year cycle, Long Now reports.

Artist Oskar J. — Read the rest

The post A 26,000-year monument hidden at Hoover Dam appeared first on Boing Boing.