Hidden Gems — Roma

An entirely ordinary-looking basilica on the surface, hiding two almost never-visited layers of Roman history right beneath it: a 4th-century church and a temple of Mithras.

A small residential district well off the tourist trail, an eclectic maze of towers, dragons, wrought-iron chandeliers, and fairy-tale frescoes.

A quiet, green cemetery at the foot of the Pyramid of Cestius, the final resting place of poets Keats and Shelley, nearly unknown to tourists.

An unassuming gate on the Aventine Hill hides one of Rome's most surprising views, framed perfectly inside a keyhole.