Domus Aurea

After the fire of 64 AD, which destroyed the greater part of the centre of Rome, Emperor Nero had a new residence built; it had walls sheathed by fine varieties of marble and vaults decorated with gold and precious stones, so to earn the name of Domus Aurea (Golden House). It was designed by the architects Severus and Celer and decorated by the painter Fabullus.

The enormous complex included boundless vineyards, pastures and woods, an artificial lake, treasures looted from the cities of the Orient, and precious ornaments, such as a statue of the Emperor in the robes of the Sun God.

At the death of Nero, his successors tried to bury every trace of the Palace. The luxurious halls were despoiled of the sheathing as well as of the sculptures and were filled with earth up to the the vaults; upon them the large Baths of Titus and Baths of Trajan were built and in the underlying valley the Colosseum was erected. The lavish fresco and stucco decorations of the Domus Aurea remained hidden until the Renaissance.

Then, some artists  passionate about antiquities, such as Pintoricchio, Ghirlandaio, Raphael, Giovanni da Udine and Giulio Romano, abseiled down into what they thought were caves and began to copy the ornamental motifs of the vaults; hence the decorations were called grotesques (from the Italian word grottesca, grotta being the Italian for cave). With the rediscovery there began to be problems of preservation of the paintings and the stuccoes, which quickly discoloured because of humidity and ended up being forgotten.

Only after the recovery of the frescoes of Pompeii did scholars again turn their attention to the Roman grotesques, and in 1772 the excavations within the Domus Aurea were resumed.

For more informations:

http://archeoroma.beniculturali.it/en/archaeological-site/domus-aurea