Pompeii has the most impressive ruins I have seen anywhere in Europe--even Athens. Left undisturbed for nearly 1700 years, it serves as a museum frozen in time, right down to the people (you can actually see plaster casts of unlucky citizens caught in the eruption still in their last defensive position). The stunning ruins include fancifully columned buildings still standing in place, fully intact floor mosaics, and colorful wall murals.
