Move FM Global News

LISBON, Portugal: Twice a year, a Lisbon street opens some steps leading to a 2,000-year-old Roman structure, the “cryptoportico” subterranean maze of tunnels and passageways, which still provides support for the buildings above and is one of the Portuguese capital’s most ancient sites.

The cryptoportico was built by the Romans in the first century AD, when the city was known as Olissipo and was under Rome’s rule for several centuries.

“This structure guaranteed and, 2,000 years later, continues to guarantee that the buildings above our heads are stable and safe for those who live, work and walk up there,” said Joana Sousa Monteiro, director of the Lisbon Museum, as quoted by the Associated Press.

Known as the “Roman Galleries,” the site opens for only a few days in April and September each year.

It was first discovered in 1771, when Lisbon was being rebuilt after the Great Earthquake of 1755.

The space is usually flooded by an aquifer running beneath the city, which brings water, essential for its preservation, but must be drained to allow access.