Archeologists have chanced upon an underground chamber decorated with images of panthers, centaurs and a sphinx in the remains of a vast palace built by the Emperor Nero in Rome.

The room, which was part of the huge Domus Aurea palace built by the emperor in the first century AD, had remained hidden for nearly 2,000 years.

It was discovered by accident during restoration of an adjacent area of the palatial complex, which was built on by subsequent emperors, including Trajan, and now lies interred beneath a hill next to the Colosseum in the historic heart of Rome.