The Fort of Our Lady of the Conception, also known as the Portuguese Castle, is a red stone fortress on Hormuz Island, Iran.

Ormuz (or Hormuz) was an important maritime city and a small kingdom near the entrance to the Persian Gulf.

The original site of the city was on the north shore of the Gulf, about 30 miles east of the current Bandar Abbas.

Although most of the roof caved in long ago, much of the lower part of the very substantial outer walls is intact, with the remains lying on different levels of the site.

The Persian Safavid king, Abbas I of Persia (1587–1629), wanted to end Portuguese rule in the south and eventually managed to convince the British East India Company to allow its ships to cooperate with his land forces to seize the island from the Portuguese in 1622.