Today visit the Hagia Sophia Musuem, which is the former Greek Orthodox Christian patriarchal cathedral, later an Ottoman imperial mosque and now a museum in Istanbul, Turkey. Built in 537 AD at the beginning of the Middle Ages, it was famous in particular for its massive dome. Then to Topkapı Palace is a large museum in Istanbul. It served as the main residence and administrative headquarters of the Ottoman sultans in 15th century. Construction began in 1459, ordered by Mehmed the Conqueror, six years after the conquest of Constantinople. Then visit to the Sirkeci Train Station. Sirkeci railway station, listed on maps as Istanbul railway station, is a railway terminal in Istanbul.

The terminal is located on the tip of Istanbul's historic peninsula right next to the Golden Horn and just northwest of Gülhane Park and the Topkapı Palace.

Afternoon visit the The Basilica Cistern is one of Istanbul's most surprising tourist attractions. This huge, palace-like underground hall, supported by 336 columns in 12 rows, once stored the imperial water supply for the Byzantine emperors. The project was begun by Constantine the Great but finished by Emperor Justinian in the 6th century.

Then back to hotel, after sightseeing and stay overnight.