1. Machado de Castro National Museum
Built directly over the Roman forum of Aeminium, this art museum is as much about the building as the collection. The absolute highlight is the cryptoporticus—a maze of underground Roman galleries that supported the forum above. Walking through these cool, dimly lit stone corridors gives you a visceral sense of the city's 2,000-year-old foundations that no textbook can match. It is an engineering marvel that remains remarkably intact.
Above ground, the collection focuses on sculpture and religious art, housing some of the finest medieval stone carvings in Portugal. The presentation is modern and airy, a sharp contrast to the dark Roman tunnels below. The museum occupies the former Bishop's Palace, and the loggia offers one of the best panoramic views over the Old Cathedral and the river, framing the city in a way that makes the geography instantly clear.
Even if you usually skip art museums, the Roman underground makes this essential. It provides context to all the other Coimbra attractions by showing you exactly what the medieval city was built on top of. The juxtaposition of Roman stone and medieval religious art perfectly encapsulates the layered history of Coimbra.