Fort Tolukko
Ternate Island, Indonesia
Fort Tolukko is a small fortification that was erected in 1522 on the east coast of Ternate facing Halmahera. It was one of the colonial forts built to control the trade in clove spices, which prior to the eighteenth century were only found in the Maluku Islands. It has been variously occupied by the Portuguese, the native Ternate Sultanate, the Dutch, the British and the Spanish. It was abandoned as a fort in 1864, renovated in 1996, and is now a tourist attraction of some renown due to its curious shape.
Fort data from Wikidata (CC0). Summary from Wikipedia (CC BY-SA).