It is the highest city in the world, declared Cultural Heritage of Mankind by UNESCO. Due to its history and splendor, Potosi during the 18th century was one of the largest and most populated cities in the world. The city was settled at the bottom of the mountain with a tremendous reserve of silver providing to the Spanish colony uncalculated fortune, but this silver mountain also claimed the lives of countless native slaves. This painful history can be witnessed by going inside the centuries- year-old mines that surround Potosi.