The ruins of the Buen Suceso church, discovered in 2008, joined to the recently discovered hospital. l. sevillano

Apple’s new flagship Spanish store — a 6,000-square-meter building in the center of Madrid — contains a genuine treasure trove in its basement. Along with stacks of mobile phones and other 21st-century gadgets designed in California and made in China, sit the remains of a hospital built six centuries ago.

The technology giant’s renovation of the building located at number 1, Puerta del Sol — formerly the Paris Hotel — led to the discovery of the outer walls of the Buen Suceso hospital, next to the church of the same name. Both buildings were demolished in 1854 to make room for the square.

The remains of the church were initially discovered during the construction of the new Sol Metro and Cercanías light rail station in June 2009, halting the project for 10 months. The ruins were subsequently preserved in the mezzanine of the station, sheltered behind glass partitions.

The 15th-century hospital won’t be quite so lucky, however. The director of the Madrid heritage department, Jaime Ignacio Muñoz of the Popular Party, explained to EL PAÍS that Apple had been instructed to change the flooring of the basement so as to “symbolically” trace the outline of these newly discovered walls.

The walls themselves will then be covered up again so the floor of the new store can be placed on top. The actual original foundations of the hospital will not be visible.

We’re not surprised to find these remains because we knew they could be there"

Muñoz also recommended that the company place an information panel in the store to explain exactly why this path has been drawn on the floor, so people who pass through (it’s still not clear whether the basement will be a commercial area open to the public or a storage area) will know that the church and hospital once stood on the site.

The San Andrés Hospital was built in the early 15th century to treat plague victims. A church was constructed beside it and took the same name. Both changed their names to Buen Suceso (Good fortune) in 1612 and underwent several reconstructions until, in 1854, they were demolished to extend the Puerta del Sol. At that time, the hospital had 60 beds.

No human remains were found during the excavation of the hospital. In contrast, when the church was excavated, diggers discovered remains from burials from the Peninsular War and the executions that followed the May 2, 1808 uprising against Napoleon’s troops in the capital.

This most recent archeological discovery hasn’t surprised the regional government, which has allowed construction to continue. The regional permit to renovate the property was issued with the possibility that archeological discoveries might be made in mind, explains Muñoz, since, after the unearthing of the church a few years ago, new ruins were expected to surface.

In June 2012, surveys were conducted, and this past February, authorities issued a permit that allowed construction work to begin. Just a month ago, the foundation of the hospital was uncovered in the façade of the building facing San Jerónimo street.

According to Muñoz, project managers briefly considered placing glass panels on the floor to allow the remains of the church to be viewed. However, the idea was ruled out because of a “lack of great interest from a visual point of view. It’s just foundations. The information that they suggest about the shape of the walls is more important.”

Even so, the ruins will “remain protected” under the floor of the Apple store, even if “they’re only interesting from the point of view of historical documentation.”

Muñoz doubts that new remains will surface, since the scope of the construction for the Apple store is “very limited” and “already over” in terms of the basement.

“We’re not surprised to find these remains because we knew they could be there. The building is located on a historic site and is protected as an area of public cultural interest, so that any action on the ground has to have the approval of the heritage department,” says Muñoz.

The Apple store in Sol does not yet have an opening date, although it could be ready in time for Christmas.