Seokguram Grotto
Korea has no soft cliffs to hollow out, so Silla builders did the opposite: they assembled a cave from scratch, fitting hundreds of cut granite blocks into a mortarless dome on a mountain summit and burying it under earth. How did eighth-century masons make dry-laid stone shed rain and stay dry inside for twelve centuries — when every modern attempt to reproduce that balance, first in reinforced concrete and then in machinery, made it wetter?
8th century CE (Unified Silla) · Mount Toham, Gyeongju, North Gyeongsang Province, South KoreaAdded September 2026