During the 16th century, the Portuguese rulers erected the first fortification, a single wall fronted by a moat which extended from the sea to the harbour. Subsequently, the Dutch rulers converted the Portuguese Fortaleza into a single bastion. They named it Zwart Bastion and built a formidable line of defence, ringing the walled town by ten bastions, which endure to this day.
A continuous rampart was built by the Dutch rulers from mid-17th century onwards and added to by the British rulers. It encircles the town and is punctuated by 14 massive bastions.
The best way to see and enjoy views of the Fort is to walk the length of the walls (allow 90 minutes). The best time to do it is during the late afternoons and early evenings. Start at the most impressive section, where the Star, Moon and Sun bastions loom over the neck of the peninsula. The ramparts south of the harbour are pierced by the Old Gate, above which is the Royal Coat of Arms of the United Kingdom; on the inner side the gate is crowned by the initials of the Dutch East India Company, VOC and its coat of arms. South of the harbor, the Zwart (Black) Bastion is believed to be the only surviving part of the original Portuguese fortifications. The circuit of the walls continues via the Akersloot and Aurora bastions to the Point Utrecht bastion, topped by a modern lighthouse. Then to Flag Rock, the southernmost point of the walls, before looping back north through the Triton, Neptune, Clippenberg and Aeolus bastions. The final section between the Aeolus and Star bastions is closed, as it is part of a military base. While some of the bastions retain their original Dutch names, the Triton, Aeolus, Neptune and Aurora bastions were renamed by the British in honour of the Royal Navy ships of the line which took part in the British seizure of Sri Lanka from the Dutch rulers during the Napoleonic Wars.