See a fort whose cannons point the wrong way
Guns facing inland, not out to sea
A small hilltop fort at Bukit Senjuang, about 2.7 km from Dutch Square, up a short flight of steps behind a residential street. Free, unstaffed, open ground.
Why it's unique
St John's Fort sits on a small hill south-east of the centre, rebuilt by the Dutch in the eighteenth century on the site of a Portuguese chapel to St John the Baptist. Its surviving bronze cannons face inland rather than out to sea, because by then the attack the Dutch expected was Acehnese and Bugis from the interior rather than a naval assault. The guns carry the founder's mark, Jan Albert de Grave, Amstelodami.
Inland-facing coastal forts are rare enough that this is the fact every account of the place leads with. It is also unstaffed and usually empty, so it is the one heritage site in the city you are likely to have entirely to yourself, and reading the founder's marks off the barrels is something you do rather than watch.
Before you go
It is up a short flight of steps behind a residential street, and there is no ticket office, no guide and usually nobody there, which is the appeal.
Read the founder's marks on the barrels. It is a five-minute walk from the Portuguese Settlement, so the two combine into one afternoon. Daylight only.