The northern end of the building covers the site of Fort Fullerton, a fort built in 1829 to defend the settlement against any naval attacks. The fort consisted of an Artillery Barrack, a house for the officers, barracks for soldiers and a 68-pounder gun guarding the entrance to the river which used to stand on the location known as Fullerton square.[10] In 1843, the fort was extended after a sandstone monolith, the Singapore Stone, with an inscription possibly dating back to the 13th century was demolished.