Located just a short 5 minute walk northeast of the historic center of Lima, the Basilica and Convent de San Francisco is a must-see church, namely for the massive catacombs contained within the crypt underground. You can take a tour of them for a nominal fee. No photography allowed. Only discovered as recently as the 1940's, the Ossuary catacombs contain thousands of perfectly organized bones and skulls all formed in neat patterns on the church's floor. They are very well preserved due to the sturdy construction of the church, preventing damage from earthquakes over the years. I can't remember the tour cost but it was reasonable. It is Peru after all. Your dollar will go far. The church grounds also contain a cloister with gardens and fountains on the premises. It's a beautiful church in baroque style. Worthy of a visit for sure!