Underground galleries of Roman origin open only on specified dates

Galerias Romanas are permanently submerged galleries located underneath downtown Lisbon. Since the absence of water could cause damage to this rare historic site, access is limited to a few days a year. The galleries date from the 1st century BC. The site was discovered after the 1755 earthquake.

Galerias Romanas are extremely popular when they are open to the public. Lines are typically limited. A technician accompanies the tours, which are free.