Nice small museum which displays remains of the ancient Roman theatre and objects of the ancient Iulia Olisipo, the Roman city of Lisboa. It is also possibile to visit the exhibition by the painter Barahona Possollo. The outside archeological area is free of charge, however the ticket for the museum is cheap, 3€.

I love Roman history and ruins. These were interesting but there wasn't a lot to see (3 euro entrance fee). The theater was partially excavated. You could walk around the exterior and get a good look at them. There was a nice 3 story interior that allowed you to get close to some items. The staff was very friendly and helpful. Other than having limited exhibits, the only negative was these awkward, seemingly random nude paintings hanging throughout the venue. I don't consider myself a prude, but the paintings seemed inappropriately out of context with the ruins. It was creepy. On the bright side, there was a sign claiming this traveling artwork will be leaving in March 2024. This museum is a take it or leave it kind of place.

The highlight of the museum is the remains of the Roman Theatre which is just outside the main museum and free to visit from the street. However, the museum itself is worth a visit as it showcases items found as part of excavations and details the history of Lisbon's Roman past. The museum is very reasonably priced and takes between 1 and 2 hours to visit.