The central attraction of this 16th-century palazzo is Francesco Borromini’s famous perspective. What appears to be a 25m-long corridor lined with columns leading to a hedge and life-sized statue is, in fact, only 10m long. The sculpture, which was a later addition, is actually hip-height and the columns diminish in size not because of distance but because they actually get shorter. And look closer at that perfect-looking hedge – Borromini didn’t trust the gardeners to clip a real hedge precisely enough so he made one of stone.

Upstairs, the four-room Galleria Spada houses the Spada family art collection, with works by Andrea del Sarto, Guido Reni, Guercino and Titian.