Fort Canning Lighthouse was built on the southern side of Fort Canning Hill to guide ships safely towards the Singapore Harbour. The first signal light on Fort Canning was a simple lantern attached to the top of the Flagstaff in 1855. The Flagstaff light was replaced by the Lighthouse in 1903 by Riley, Hargreaves & Co., who in 1909 combined with another company to form United Engineers that is still present to this day at nearby River Valley.