The Dubai Museum in Bur Dubai, dwelling in the Al-Fahidi Fort was constructed in 1787 to preserve Dubai Creek. The walls of the citadel are built from coral and shell from the sea, and bonded together with lime. The upper floor is sustained by timber poles called handels and the ceiling is made of palm fronds, muck and plaster. The citadel has served as the home of the Ruler's family, the seat of government, stronghold and jail. The Al-Fahidi fortification was refurbished in 1971 and then widely in 1995. The patio of the Dubai Museum has numerous boats and a palm-leaf home with a conventional wind-tower. Many outsized display antechambers are found beneath the fortress. The diverse displays include a stunning display portraying the submarine world of pearl plunging as well as relics such as copper, alabaster and earthenware found in 3000 - 4000 year old graves at Al Qusais.