Mausoleum** of Galla Placidia, Ravenna, Italy. Date: c. 425–433 AD. Medium: brick chapel with interior glass tesserae mosaics and alabaster windows. UNESCO World Heritage, part of the Early Christian Monuments of Ravenna. Photographer: vvoe via Shutterstock. ** not actually a tomb. this tiny building was an oratory attached to Santa Croce, and Galla Placidia died in Rome, not Ravenna. for centuries visitors were shown a seated embalmed body through a peephole, said to be hers; in 1577 a candle mishap reportedly set it on fire and ended the legend.