Museu do Teatro Romano (Roman Theatre Museum)

The Museu do Teatro Romano preserves the excavated remains of Lisbon's Roman theatre, built into the Alfama hillside during the reign of Emperor Augustus in the 1st century CE and enlarged under Emperor Nero in 57 CE, according to a dedicatory inscription found on site. The theatre could seat an estimated 3,000 to 4,000 spectators and served the Roman city of Olisipo, the predecessor settlement to modern Lisbon, until it fell out of use and was gradually buried and built over during the following centuries. Its remains resurfaced after the 1755 earthquake, when clearance work exposed sections of the structure, but systematic excavation did not begin until the 1960s and continued through further digs in the 1990s that uncovered the orchestra, part of the cavea seating, and sections of the stage building. The museum, opened in 2012, is built directly over and around the excavation, allowing visitors to walk along suspended walkways above the exposed stonework while galleries in the adjoining historic townhouse display finds from the site, including inscribed marble fragments, ceramics, and coins spanning the Roman through medieval periods. The presentation is organized as a single chronological narrative from the Roman theatre's construction through its abandonment and the later medieval and Pombaline-era structures built above it, making it as much a stratigraphic record of Lisbon's continuous occupation as a theatre exhibit. Given the site's location within a dense residential block of Alfama, the excavation is unusually compact, and ongoing conservation focuses on stabilizing exposed masonry against moisture from the surrounding hillside.