18:00 · Sultanahmet Meydanı — Sultanahmet Square
You board the open-top double-decker bus at the stop in Sultanahmet Square. You put on the audio guide headset and choose your own language from 8 options. If you want to sit on the upper deck, it pays to arrive early; bring a light layer for the evening chill.
Beylerbeyi Palace
The bus crosses the Bosphorus Bridge from the European side to the Asian side; on the bridge, the lights of both shores of the Bosphorus come into view at once. On the Asian side, you pass in front of Beylerbeyi Palace and turn back. The palace's illuminated waterfront façade is one of the most photographed spots on the tour. You get to see two continents in the same evening.
Sultanahmet Camii — Sultanahmet Mosque
The bus returns to the starting point and the tour ends here. In Sultanahmet, Hagia Sophia, the Sultanahmet Mosque and the Basilica Cistern are within walking distance; you can make time for dinner at the surrounding restaurants.