The Asamblea Legislativa (tel. 506/2243-2000, www.asamblea.go.cr [1], free) occupies three buildings on the north side of the plaza on Calle 15. The blue building—the Castillo Azul—to the east was originally the presidential palace, built in 1911 by presidential candidate Máximo Fernández in anticipation of victory in the 1914 elections. He lost, then lent his home to president-elect Alfredo González Flores as his official residence. Later it served as the U.S. Diplomatic Mission.
Behind it, the Casa Rosada (Pink House), dating from 1833, has two rooms with galleries of paintings and photographs of past Costa Rican presidents. The Edificio Central (main building), built in 1937, houses the Congress, or legislative assembly.
Guided visits are offered 8 a.m.–4 p.m. Monday–Friday (tel. 506/2243-2000, rruiz [at] congreso [dot] aleg [dot] go [dot] cr or http://bit.ly/aCRftv [2]). A dress code applies: no sandals or shorts (for men), nor miniskirts for women. Cameras are permitted, without flash.
Links:
[1] http://www.asamblea.go.cr
[2] http://bit.ly/aCRftv