Near ancient Rome’s first port (Portus Tiberinus) and the adjoining cattle market (Forum Boarium) was a vegetable market named Forum Holitorium. Facing it were three Republican temples dating from the 3rd century BC. The church of San Nicola in Carcere was built over these temples. Yet the architect incorporated the columns of the two outer temples – the Temple of Janus and the Temple of Spes – into the façade of the new church. Exposed here are the columns from the Temple of Spes. Saint Nicholas in Prison originated in the 7th century and was rebuilt in 1128 and again in 1599. This church offers a fascinating underground tour to see structures and foundations that are over 2,000 years old.