Square Tower, Colonial defensive building at Waterfront, Kuching, Malaysia.

The Square Tower is a fort in Kuching, Sarawak, Malaysia. Built in 1879 as a prison, it was later turned into a fortress. The building bears the Brooke era coat of arms.

The structure was completed in 1879 under Charles Brooke's direction and first served as a prison featuring dungeons for holding inmates. It was later converted into a fortress and eventually became a venue for social gatherings and events.

The building displays symbols from the Brooke era and blends British colonial design with regional Malaysian architectural elements that remain visible today. This combination allows visitors to see two different building traditions meeting in one structure.

The location sits right on the riverbank and is easily accessible from the city center, making it convenient to visit as part of a walking tour. Visitors should know the interior spaces are modest in size and there is limited shade outside, so it is better to visit during cooler parts of the day.

The Square Tower carries the Brooke era coat of arms on its facade, a heraldic panel from the White Rajah period that visitors often walk past without noticing. It marks the building as part of the Brooke administration's riverside ensemble in Kuching.