Casa de las Trece Monedas (Ancash 536, closed to the public) was built in 1787 and gets its name from the 13 coins in the coat of arms on its facade. Nearby is Plaza Bolívar, flanked by Peru’s congress building and graced with a bronze statue in honor of liberator Simón Bolívar.
On the far side of the plaza is the interesting Museo de la Inquisición (www.congreso.gob.pe/museo.htm [1], 9 a.m.–5 p.m. daily, free), which served as the headquarters of the Spanish Inquisition from 1570 until it was abolished in 1820. The museum explains the harsh and bizarre punishments that the church doled out for crimes ranging from heresy and blasphemy to seduction and reading banned books.
There are creepy dungeonlike spaces in the back where the punished were given 50 lashes and jailed while others were sent to work on slave ships or in public hospitals. This was also where autos-da-fé were ordered—public condemnation ceremonies in the Plaza de Armas where witches, bigamists, and heretics were hung to death or burned at the stake.
Links:
[1] http://www.congreso.gob.pe/museo.htm