This was the first nucleus of the MUHBA, and opened to the public in 1943. The remains within it range from items from Roman Barcino in the 1st century BC to the Barcelona of the 13th century A.D.and to the early Middle Ages. Visitors to this underground area can walk along the streets of Roman Barcelona, past the city wall; they can look around a laundry from the 2nd century A.D. and see the remains of the city's first Christian community, as well as other spaces. This site also features some important medieval buildings, such as Palau Reial, the Chapel of Santa Àgata and Saló del Tinell, in addition to the Gothic mansion of Casa Padellàs, originally located in another part of the city. The latter building is now used for temporary exhibitions on modern and contemporary Barcelona.