The Catedral Metropolitana Nossa Senhora da Conceição sits on a small rise above the port, its white-and-yellow neoclassical facade visible from the river. The original Jesuit chapel on the site was built in the 1690s; the present building dates from a reconstruction completed in 1878 after fire destroyed the older church.
The interior is plain by Brazilian cathedral standards — barrel-vaulted ceiling, simple marble altar, and stained glass that floods the nave with coloured light in the late afternoon. The square outside, Praça Oswaldo Cruz, is one of the few patches of shade in the centre and a good place to pause between sights.