Raffles lighthouse in the Singapore Strait, located on an islet called Pulau Satumu ("One Tree Island") & completed in 1855. The photo was taken in July 1979. The height of the white lighthouse tower is 29m and the white light flashes 3 times (in quick successtion) every 20 seconds.
Compared with the more recent photo taken from a similar angle at https://360click.deltathailand.com/delta-collaborates-with-m1-for-hybrid-system/, it can be seen that since my photo was taken there has been a considerable increase in the number of trees (so should the island be renamed?) and the red & white lattice tower (radar tower?) has been added