Hagia Sophia has spent fifteen centuries confounding expectations. Built by Emperor Justinian I in 537, it was the largest cathedral in the world for nearly a thousand years. When the Ottomans took Constantinople in 1453, Mehmed II rode inside on horseback, had sand thrown on the floor as an act of humility, and converted it into a mosque. In 1934, a museum. In 2020, a mosque again.

The building holds surprises most visitors miss. Tucked into a marble gallery upstairs is a runic inscription by a Viking called Halfdan, a Scandinavian mercenary who served as an imperial bodyguard and felt compelled to record the fact. Around him rose the mosaics, minarets and vast dome that successive rulers have claimed and reclaimed ever since.

VoiceMap's self-guided audio tours unpack Hagia Sophia's layered history and place it in the broader sweep of Istanbul, from Byzantine foundations to Ottoman transformation and beyond.