I can’t leave this site out of my posts, even though I have left Naples.
Herculaneum is a smaller site than Pompeii, and less crowded. Destroyed by the same eruption of Mt Vesuvius as Pompeii, the buildings are more recognizable, the colours of fresco remnants more vivid. It is easily reached from Rome and Naples.
And, for those with time to spare, and a sense of curiosity, a documentary about this site.