Photo: Ypsilon from Finland, CC0 via Wikimedia Commons
Goes along the seashore with a beautiful white handrail all the way.
© OpenStreetMap contributors
Museo del Azulejo
19th-century tiles are on display in the tile museum. At Paseo San Gabriel just behind the museum, there is a beautiful map of Colonia as it looked in 1762 painted on tiles.
Casa del Virrey
Reconstructed somewhat on the ruins of the original building. Don't miss the whale skeleton on display just to the west of it!
Museo Municipal Dr. Bautista Rebuffo
Museum in two floors presenting objects of daily life 200 years ago as well as the works of scientists and explorers that have lived and worked in the town. In the room dedicated to a biologist there are various two-, six-, and eight-legged creatures on display, as well as small and very large fossils. If you're lucky you get to meet the offspring hanging next to the fusebox in the back corner. This museum is also where you buy the U$50 ticket that allows you into all eight museums.
Casa de Nacarello
A Portuguese 18th-century building: an example of a furnished home from those times.
Archivo Histórico Regional
The house was built by the Portuguese in the 18th century and called "Casa de Palacios". The museum shows documents from the various epochs in Colonia's history.
Small brick ruin between the lighthouse and the main square. You would not know what kind of building it was if there weren't a sign next to it.