Here, Muhammad Ali waited while his forces trapped, and put an end to the Mamluk beys by massacring most of their leaders as they were leaving the Citadel. The Kasr (Qasr) El-Gawhara or Jewel Palace, originally Mohammad Ali Pasha's headquarters, is now open to the public as an example of the best early 19th century Ottoman decoration and architecture. Its collection includes 19th century royal portraits, costumes and furnishings. Constructed in 1814, it includes a small garden leading to a mosque with one of the more interesting eccentricities being the Watch Hall where the shape of a watch has been used to decorate the walls.