The neobaroque palace north of the Plaza de Armas is the official residence of the president. It was built on the site where Francisco Pizarro was murdered in 1541, and has undergone several reconstructions, the most recent of which was completed in 1938. The best time to visit is at noon, when you can watch soldiers in red-and-blue uniforms conduct an elaborate changing of the guard. It's not Buckingham Palace, but it's impressive. Tours are offered on Saturday at 10 and 11, but you should call to reserve at least a few days ahead of time.
Conde de Superunda 1501, Lima, 01, Peru