The central part of the coastal desert of Peru, where Lima is located, witnessed the formation of the first civilization in South America. Just 100 km north of Lima lays Caral, the first city in the continent, dating from 5,000 years ago.
It took till the mid 19th century for this republic to experience its first economic boom, with the guano (birdshit) trade. Big mansions were erected in Jr de la Union (walk 2) and other parts of downtown Lima and the villages Miraflores, Barranco and Chorrilos became fashionable summer resorts. This is all ended in the war with Chile in 1879. The resorts were destroyed and Lima was occupied for a couple of years.
Some very nice examples of totalitarian brutalist architecture from the 70-ies can be found in San Borja; Pentagonito, Museo de la Nación. The 80-ies and the 90-ies were not good decades for architecture; there was no money, so buildings are in every sense poorly executed.