The most popular day trip from Bogotá, 50km north, Zipaquirá is a cute historic town noted for its salt mines, particularly the one fashioned as a surreal walk following Jesus' last steps and finishing in a stunning three-part cavernous cathedral 190m below the ground, highlighted by the largest cross ever built in an underground church. Salt was a major resource in this area before the Spanish showed up in those metal hats, and local mines still churn out 40% of Colombia's salt resources.
In the mountains about 500m southwest are two underground cathedrals carved out of salt. The first opened in 1954, then was closed in 1992 for safety reasons. The newer Catedral de Sal, built between 1991 and 1995, sits within the larger Parque de Sal complex (a sort of salt-theme playground – a bit cheesy) and is Bogotá's most memorable day trip.