Fort Tahula stands on a ridge directly above Soasio, the main town of Tidore, and is the most accessible of the island's Spanish-era forts. A short climb up a stone-paved path from the town leads to the surviving walls and bastions, which still trace the outline of the original star-shaped plan. The interior is largely ruined but the views across the strait to Ternate's volcanic cone are excellent, and the breeze at the top is a welcome change from the heat of town.
Allow about an hour for the climb and a wander among the ruins. There is no entrance fee and no formal interpretation on site — the caretaker, if you find him, can sometimes show you the foundations of the powder magazine and explain how the fort was supplied during sieges. Bring water and go early or late in the day; the climb is steep and the sun is unforgiving by mid-morning.