The lighthouse, technically Ras Umm Sid lighthouse, is the most visible structure in central Sharm. The white tower stands on the headland that separates Naama Bay from the Old Market, marking the entrance to the Strait of Tiran for ships heading north into the Gulf of Aqaba. It is still functional and not normally open to the public.
The reason it ends up on visitor lists is the reef beneath. The wall directly below the lighthouse, accessible from a small public beach, is one of the easiest world-class snorkelling sites in Sharm — you walk out a few metres and the bottom drops away in a tower of coral. It is also a popular shore dive for beginners. The clifftop above is a popular sunset spot and gives the best wide view of the Sharm coastline.