The Convento da Ordem do Carmo or Carmo Convent is a medieval convent that was ruined in the 1755 Lisbon earthquake, one so powerful it almost destroyed the entire city. The ruins of its Gothic style church are the most obvious trace of the earthquake. The two buildings were founded in 1389, and were completed in 1423.
I found the ruined main nave of the church fascinating. Walking around the inside, you clearly get an idea of how strong the design was as you look up at the remaining pointed arches.
Today, the church is an archaeological museum, the Museu Arqueológico do Carmo or Carmo Archaeological Museum.
This was one of my favourite experiences that I had in Lisbon. I highly recommend checking it out in person, but check out my photos below.