Casa Viola is one of the oldest houses in Asuncion — a low colonial building with thick adobe walls that sits in the Manzana de la Rivera complex near the riverfront. The building dates from the early colonial period and now houses the Museo Memoria de la Ciudad, a collection of maps, photographs, and documents that trace the history of Asuncion from its founding in 1537 to the present.
The museum is small but worthwhile, particularly for the historical maps that show how dramatically the city has changed. The Manzana de la Rivera complex of which it forms a part includes several other restored colonial buildings connected by gardens — a pleasant circuit in its own right, and one of the few places in the city where you can get a real sense of what colonial Asuncion looked like.