Pompeii, Italy

One of the most famous eruptions of all time, Mount Vesuvius' 79 A.D. eruption completely buried the ancient Roman city of Pompeii under a thick blanket of volcanic ash.

The city was abandoned for nearly 2,000 years, until explorers discovered it fully intact underneath 20 feet of dirt and debris in 1748.

Many of the abandoned structures are still standing today, and can be visited.