Mosque of Sultan Hassan

An enormous stone mass below the Citadel, and the most imposing medieval building in Cairo. Everything about it is oversized: walls thirty-six metres high, an entrance portal that swallows you whole, and an interior scaled to make a person feel small — which was exactly the intention.

Inside, four great vaulted halls open off a square courtyard, one on each side. Each was a school for one of the four Sunni schools of law, with its own students and teachers living in the multi-storey cells stacked behind it. It is a university built as a single enormous room.

Look for

• The portal, deeply recessed and carved with stalactite vaulting
• The mausoleum behind the qibla wall — the finest space in the building, with an inlaid marble floor and a soaring dome
• The bronze-plated doors and the chains once hung across the entrance
• Al-Rifa'i Mosque directly opposite, built five centuries later in deliberate imitation, so the two face each other across a narrow lane

Construction began in 1356 under Sultan Hassan, a boy who came to the throne at thirteen and ruled, on and off, as a figurehead for competing Mamluk factions. The building was ruinously expensive — contemporaries recorded that it nearly emptied the treasury — and the money is thought to have come substantially from the estates of people who had died in the Black Death without heirs, which by law reverted to the state.

Egypt lost perhaps a third of its population to the plague in 1348. This building is, in a very direct sense, what was done with the property they left behind.

The empty tomb

Sultan Hassan was murdered in 1361, two years before the mosque was finished. His body was never recovered, and the magnificent mausoleum built for him at the heart of the complex has never held him. Two of his sons are buried there instead.

A fortress by accident

Its position below the Citadel made it a military problem. Rebels repeatedly used the roof and minarets as a firing platform against the fortress above, and on more than one occasion the authorities responded by demolishing parts of it. One minaret collapsed in 1361, killing hundreds; a later one was pulled down deliberately.

The stone, incidentally, is not all new: some of the facing is believed to have been taken from the casing of the Giza pyramids.