Chùa Quán Sứ

This guide to Chùa Quán Sứ in Hanoi opens with a puzzle: a fifteenth-century royal guesthouse built for tribute-bearing envoys from Champa and Laos, with no temple in sight, until a small chapel went up beside it almost as an afterthought so the visiting Buddhists would have somewhere to pray. It follows what became of that guesthouse as dynasties fell, and traces the modest side building through an 1822 renovation that opened its doors to ordinary Hanoians. Not one brick of the original guesthouse survives on the grounds you're standing in.