Medusa Heads and a Sinking Palace

Justinian, the 6th century Byzantine emperor, built a system of cisterns beneath the city of Constantinople, now Istanbul in Turkey. One of these cisterns, dubbed the "sinking palace" by locals, can be seen by visitors, and is unusual because the cistern itself resembles an abandoned palace. It is one of several hundred cisterns which lie beneath a thriving metropolis of trams and city streets.
The 336 Roman columns supporting the massive structure are what give the cistern the look of a...