Tekfur Palace is the only Byzantine palace in Istanbul still standing whole, three storeys wedged into the gap between the double land walls near Edirnekapı. Its outer face is a textbook of late Byzantine taste, red brick laced with white marble. Inside you climb three storeys of a museum built into the shell. The rooms stood roofless and open to the sky for centuries, so nothing Byzantine survives in them.
It went up in the decades around 1300 as an annex of the sprawling Blachernae Palace, seat of the empire's last rulers, and it doubled as a strongpoint where two lines of fortification meet. After 1453 it passed through a strange run of lives: a menagerie of exotic animals, a poorhouse, a bottle workshop. In the early 1700s a kiln here fired the Tekfur tiles that tried to revive the fading art of İznik. The roof and floors you walk on were rebuilt by 2014, and the museum opened in 2019 with tiles fired on this ground on display.