Set on the tip of the Anfushi/Pharos promontory, looking back over the eastern harbour and downtown Corniche. It was built by Mameluke Sultan Abdul-Nasser Qa'it Bay in 1477 CE, by re-cycling the stone of the ruined lighthouse. It tried (with limited success) to defend the city against invaders, from crusaders to Napoleon, and was in military use as late as 1882, when the British bombarded it.There are two entrances and admissions. West, facing your approach along the Harbour mall, is the ground-floor Maritime Museum - this is of little interest. (Its collection continues in a building on the mall.) Come round to the south flank facing the Corniche for the main entrance into the Citadel. There's a fortified courtyard then a 4-storey bastion.