2. Mexico’s Natural Underground Springs

The Yucatan Peninsula is quite rare in its construction and distinctive, with its porous limestone shelving creating large tunnels and sinkholes reaching to the depths of the Earth. These natural underground tunnels are called cenotes, and the Yucatan Peninsula is home to two thousand of them, often linked by underground rivers. In ancient times, these cenotes were the primary water source, and were also symbolically significant as they were seen as passageways to the underworld. The ethereal feeling these other-worldly rivers produce draws thousands to explore them each year.