Cistern Basilica -- a very fancy well

Istanbul's most unusual sight: an elaborate cistern.
We couldn't resist taking some time from the soaring mosques and gilded church ceilings to go underground to look at a Byzantine cistern. Using Roman engineering including aqueducts and cisterns the Byzantine-era city fathers set up a huge underground reservoir that made the city seige-proof.

In later years the cistern was forgotten --until officials got wind of residents who'd figured out that if they dug a hole in their basements and lowered a bucket -- they would be rewarded with water and sometimes even fish. The cistern was then partially restored and repaired.

The question is why the builders went to such lengths! Columns with doric, ionic and corinthian tops, gorgeous design and most odd --in the farthest corner of the cistern -- at the bottom of the cistern two colossal carved stone heads of Medusa. Maybe this was a charm against evil, or maybe a secret shrine to water nyphs. But such workmanship for a place meant to be dark, underground and under water is difficult to explain. It's paid off in a great tourist attraction now, however. They've put in mood lighting and a walkway so you can wind your way around the columns and they play classical music so it's eerie and memorable. Most people, of course, toss coins into the water these days.