Amsterdam Castle, originally the Amsterdam Armory, was built in 1895 by the prolific upstate architect Isaac G. Perry in the Late Victorian castellated style — a six-storey octagonal tower, crenellated walls, and the general impression of having been transplanted from the Rhineland. It served as a National Guard armory until 1994 and was then repurposed as an event venue and boutique hotel.
The interior includes a grand drill hall, a chapel, and a museum room of regimental memorabilia. Tours are offered by appointment; if it is closed, the building is striking enough from the outside to be worth a five-minute detour. It sits at the intersection of Florida Avenue and Dewitt Street, a short drive west of the centre.