Roughly a half hour train ride from Naples you'll find Pompeii. During my first visit to Europe, with 8 countries under the belt, this was the monument that my friend found stuck out the most for her. When Mount Vesuvius erupted in 79 AD, the city of Pompeii found itself covered in 4-6 of volcanic ash and pumice, desecrating the city and reducing the population to zero. Pompeii remained lost for years, until the first discovery of it in 1599. Since then there have been varying degrees of excavation. For my friend and I, what we found amazing is that while we spent an entire day roaming the streets, we'd only a small fraction of the city that once was - work is still ongoing to excavate the city. PLEASE, bring sensible footwear, water and if it's hot and sunny, consider taking an umbrella for shade. While portions are doable if someone in your party uses a wheelchair, know that this is not a completely accessible site.