The House of Neptune and Amphitrite is one of Herculaneum's most rewarding small stops, named for the brilliant glass-paste mosaic of the sea god and his wife in the rear courtyard. The colours are still vivid, and the house gives a good sense of how wealthy residents used decoration to turn domestic space into theatre.
It sits within the excavated Herculaneum site, close to several other preserved houses. Do not rush past it while following the main streets; the mosaics are among the best in the ruins.