Santa Marta, Colombia -- La Ciudad Perdida (The Lost City). Hidden (literally) in the crevices of northern Colombia’s Santa Marta Sierra Nevada mountain range, La Ciudad Perdida was built by the Tayrona people around 800 AD. Although built approximately 600 years before Machu Picchu, it was “discovered” by looters on the hunt for treasure in 1975 (60 years after Machu Picchu’s “discovery”).
In the year 79 AD, Italy's Mt. Vesuvius erupted with superheated ash that rained fiery death on several Roman cities nearby. But none was hit harder than vacation town Pompeii, which was buried in a thick layer of broiling ash in a matter of seconds.