Flagstaff House, the former summer residence of the British Governor-General of India, is one of the best-preserved examples of colonial architecture in the Barrackpore cantonment. The house dates from the late 18th century and sits within spacious grounds on the Hooghly riverbank. Governors would retreat here from the heat and politics of Calcutta, and the property saw visits from nearly every major figure of the British Raj, including Lord Clive and Warren Hastings. The grounds include a large garden and a small zoo that later became part of the state complex.
The building is now used as an official state guest house and is not generally open to visitors, but the gate and exterior are visible from the road. The approach through the cantonment streets — lined with large trees and the occasional colonial bungalow — is worth the short walk in itself.