Being the central post office of Kolkata, the General Post Office is in charge of most of the inbound and outbound letters and parcels of the city. Designed by Walter B Grenvile (who was consulting architect to the Indian Government between 1863 and 1868) in 1864 and completed in 1868, it has towering ionic-corinthian pillars that are hailed for their grandeur. Its high-domed roof, rising to 220 ft, is also well-known. The dome has a huge clock on it and it is supported by an octagonal base and 28 Corinthian pillars. The cost of construction of the General Post Office is pegged at Rs 6,30, 510.

The introduction of the postal system was done by Warren Hastings in 1774. In 1884, a postal museum was created that displays a fine collection of stamps and artefacts.