Grand Bazaar

Hagia Sophia(1 km)(0.6 mile)
Hagia Sophia is a 6th century Orthodox patriarchal basilica that was later used as a mosque, and is today a museum.

Topkapi Palace(1.4 km)(0.8 mile)
TheTopkapi Palace was the primary residence of the Ottoman Sultans for approximately 400 years of their 624-year reign.

Galata Tower(1.7 km)(1.1 mile)
It was built by the Genoese on the city walls of Galata, then a western (Genoese/Venetian) stronghold beside eastern (Byzantine/Ottoman) Constantinople.

Patriarchate of Constantinople(2.4 km)(1.5 mile)
Arguably the centre of World Orthodoxy, housed since 1586 in Church of St George (Greek: Agíou Geōrgíou, Turkish: Aya Yorgi), which is, despite its religious importance, an otherwise unremarkable and unimpressive building from outside, though its lavishly decorated interior is worth a look.

Soğukçeşme Street(1.1 km)(0.7 mile)
A car-free downhill cobbled street just behind Hagia Sophia, with renovated (or totally re-built) traditional wooden houses two- or three-storeys tall typical of Ottoman era, leaning against the outer wall of Topkapi Palace grounds/Gülhane Park.

Museum of Turkish and Islamic Art(0.8 km)(0.5 mile)
Carpets, rugs, calligraphy, pottery.

Million(0.6 km)(0.4 mile)
While this partially intact marble pillar dating back to 4th century AD may seem unremarkable, it was the starting point of any distance measured within the empire during the Byzantine era, so it may be nice to think that you are in the centre of where all the roads lead to (or, rather, start from).

The Museum of Archeology(1.2 km)(0.7 mile)
A must see! One of the best, including a great collection of Sumerian tablets, pieces of the wall of Babylon and Roman marble statues.