The Old City of Istanbul (Turkish: Eski İstanbul, “Old Istanbul”, also Tarihi Yarımada, “Historic Peninsula” and Suriçi, “Walled City”) is the oldest part of the city, and the location of most of its historic sights.
Being a peninsula bounded by bodies of water to the north, east, and south (the Golden Horn, Bosphorus, and the Sea of Marmara, respectively) and by the old city walls to west, this part of the city is essentially what used to be called Constantinople. The rest, of what is today Istanbul, were independent cities, towns, villages, fields or even complete wilderness later absorbed by the city. This process is still going on as Istanbul grows with an increasing speed.
The construction of Yenikapı train and subway station, from 2004 to 2014, on the southern coast of the peninsula, revealed archeological finds that date the very first time of Istanbul’s settlement back to about 8000 years ago, which makes the city one of the oldest still-inhabited spots of the world. However, tradition states that Byzantium was first settled by Greek colonists from Megara on the Greek mainland in 667 BC. According to this tradition, they and their leader Byzas consulted the Delphi oracle, who said they would create a great harbor city “across from the land of the blind”. After much sailing, they arrived at the strategically superb peninsular site of Seraglio Point (Sarayburnu) and encountered some fishermen who told them they lived in Chalcedon, a very less privileged site across the Bosphorus. (“They are the blind!”, said Byzas to himself). This spot that the Megarans chose to found their new colony is now occupied by Gülhane Park and the Topkapı Palace. The urban area was greatly expanded by Constantine the Great for his Imperial capital, inaugurated on 330 AD: foundations of the Constantine walls were uncovered by the digs for Yenikapı station.
Once the starting point of the Hippie Trail, the Sultanahmet area has been the main tourist district of the city since the 1960s. As the Hippodrome of Constantinople, it was for long one of the main social centres in the city — a role it still temporarily plays for the evening feasts during the Ramadan — and hence is a part of the old city with an exceptionally disproportionate number of historic sights. The name of the district derives from the Turkish name of the imposing Blue Mosque on one side of its main square, which in turn is named after the Ottoman sultan Ahmet I (r. 1603–1617), who had the mosque built, and is buried in a mausoleum on its grounds.
Parts of the peninsula was declared a World Heritage Site by UNESCO in 1985.