Domus Aurea

The domus aurea made an innovative use of mosaics. Previously, mosaics had been used for floors, but Nero used mosaics elsewhere, as well, including on the ceilings. Joyce says the use of mosaics for walls and vaults came from grottoes to the nymphs, where mosaics resisted the damp and exposure.

For more on Roman innovations in mosaics, see:
"Form, Function and Technique in the Pavements of Delos and Pompeii," by Hetty Joyce (American Journal of Archaeology © 1979).