Archaeologists excavating the site of a planned 32-story skyscraper in London uncovered the ruins of a nearly 2,000-year-old Roman basilica. 

The ancient basilica, constructed between 78 and 84 A.D., once stood at the heart of the city, which was known at the time as Londinium, according to The Associated Press.

While exploring the basement of a building slated to be demolished for the upcoming office tower, the scientists unearthed the remains of what once served as the foundation of a two-story building, nearly as large as an Olympic swimming pool. 

They uncovered flint, brick and ragstone walls and foundations 13 feet deep and more than three feet wide, AP reported.

“We’re talking about the early stages of London here, but it’s a real sign of investment in the city, even in its early infancy,” added Henderson-Schwartz.

In this photo provided by Peter Marsden is a drawing of a representation of the Roman London Basilica, which was recently unearthed during a redevelopment project for a building in London.  (Peter Marsden via AP)

Further excavation could answer questions about the original forum and why it was replaced with a larger one after only 20 years of use. It could also offer glimpses into the lives of Roman Londoners, according to AP.

The owner of the site, developer Hertshten Properties, has agreed to display the ruins in a visitor center of the planned office tower, AP reported. Property developers in Britain have to consult archaeologists in their planning process.

“We do have these little windows into Roman London that are all over the city,” Henderson-Schwartz said. “But this is really in some ways the site that connects them all together.”

The Associated Press contributed to this report.