Speculum Alchemiae

This guide to Speculum Alchemiae in Prague starts with a 2002 flood that pulled back to reveal a hole in an Old Town street, leading workers into hidden underground rooms sealed for centuries and stocked with broken glass vessels and a mummified crocodile. You'll hear about Emperor Rudolf the Second's court of alchemists chasing the philosopher's stone in the 1580s, among them the Englishmen Edward Kelley and John Dee. A locked doorway past the first chamber is said to lead toward Prague Castle, worth pausing at even though nobody has walked it in years.