4 Best Sights in Istanbul, Turkey

The major problem with the site of Byzantium was the lack of fresh water. So, for the city to grow, a great system of aqueducts and cisterns was built, the most famous of which is the Basilica Cistern, whose present form dates from the reign of Justinian in the 6th century. A journey through this ancient underground waterway takes you along dimly lit walkways that weave around 336 marble columns rising 26 feet to support Byzantine arches and domes, from which water drips unceasingly. The two most famous columns feature upturned Medusa heads. The cistern was always kept full as a precaution against long sieges, and fish, presumably descendants of those that arrived in Byzantine times, still flit through the dark waters. A hauntingly beautiful oasis of cool, shadowed, cathedral-like stillness (with Turkish instrumental music playing softly in the background), the cistern is a particularly relaxing place to get away from the hubbub of the Old City. Come early to avoid the long lines and have a more peaceful visit. This site is closed for renovations as of spring 2022. Check the website for updates.

The walls of Constantinople were the greatest fortifications of the medieval age and, although they were severely damaged by Sultan Mehmet II's canon in the siege leading up to the Ottoman conquest of the city in 1453, large sections still stand more or less intact. The walls were built in the 5th century after the city outgrew the walls built by Constantine, and they stretched 6½ km (4 miles) from the Sea of Marmara to the Golden Horn. The "wall" was actually made up of a large inner and smaller outer wall, with various towers and gates, as well as a moat. Parts have been restored, and you can even climb around on top; the easiest section on which to do this is near Edirnekapı, a short walk uphill from Chora.

It takes a bit of imagination to appreciate the Hippodrome—once a Byzantine stadium for chariot racing with seating for 100,000—since there isn't much here anymore. Notably absent are the rows of seats that once surrounded the track and the life-size bronze sculpture of four horses that once adorned the stadium (the Venetians looted the statue during the Fourth Crusade). You can, however, see several other monuments that once decorated the central podium. The Dikilitaş (Egyptian Obelisk) probably marked the finish line. The very partial Yılanlı Sütun (Serpentine Column) was taken from the Temple of Apollo at Delphi in Greece, where it was dedicated after the Greek victory over the invading Persians in the 5th century BC. The Örme Sütun (Column of Constantine Porphyrogenitus) was once entirely covered with gilt bronze, which was stripped off by vandals during the Fourth Crusade. Closer to the tram stop is a much more recent addition: a neo-Byzantine fountain that was a gift from the German government in 1901, commemorating Kaiser Wilhelm II's visit to Istanbul three years earlier.

A Roman city needed its aqueduct, and Constantinople, which seriously lacked drinking water, finally got one in 375 under Emperor Valens. The aqueduct, which was just one element of a well-engineered water distribution system that extended for miles, was restored in the 16th century by the Ottoman architect Sinan and continued to function well into the Ottoman era. The best and most dramatic surviving section is that near Şehzade Mosque, where Atatürk Bulvarı, a major urban thoroughfare, passes through the great arches of the aqueduct—still one of Istanbul's most significant landmarks.