The flagstaff on Government Hill (present-day Fort Canning) was used to signal the arrival of vessels. It was part of a system of flagstaffs at sites with a commanding view of the entrances to the Singapore River and Harbour. Other flagstaffs were on Mount Faber and Pulau Blakang Mati (present-day Sentosa). The flagstaff on Government Hill was also used to signal the arrival of mail vessels, which in the 1840s took more than a month to convey mail from London to Singapore. A red ensign indicated mail from Europe and a yellow flag, the China mail.
