Archaeologists exploring the site of a planned 32-story office tower announced Thursday that they have unearthed the remains of a Roman basilica that once stood at the heart of the city known as Londinium.

An office building from the 1930s in London was about to be demolished — until remnants of the city’s first Roman basilica were found in the basement.

While preparing for demolition of one office building and construction of another right in the heart of London, workers just uncovered remains of the city's original Roman basilica. Built circa 80 C.E.