The center of tourist attractions in Istanbul is Sultanahmet Square. On one side you have Hagia Sophia, on the other the Blue Mosque, and right beside that the Hippodrome, all a hop and skip away from the majestic Topkapi Palace. What you don’t see - and I walked past it on my first visit to Istanbul - is that right next to Hagia Sophia: an underground forest of Roman columns called Basilica Cisterna.
I visited the ruins of the Mausoleum of Halicarnassus, one the Seven Wonders of the Ancient World, in Turkey, and the statues which used to be there and are now in the British Museum.