The place was called the Topkapi Palace Harem in Istanbul, also known as the Harem at Topkapi Palace. It was the private domestic section of the Ottoman sultans’ palace.

Quick context

  • Topkapi Palace was the main Ottoman imperial palace in Istanbul.
  • The Harem was the secluded residential area inside it, not a separate palace.
  • In official descriptions, it is also referred to as Dârü's-saâde or the House of Felicity.

In plain English

If you were asking where the harem was located, the simplest answer is: inside Topkapi Palace, in Istanbul.

TL;DR: It was the Topkapi Palace Harem in Istanbul.