Geothermal Pools, Yellowstone National Park, USA: Old Faithful draws the masses, but a more interesting and varied foray into the geothermal wonders awaits along the boardwalk trail of West Thumb Geyser Basin. Here, Morning Glory Pool.
Some of our planet's most unsuspecting elements are responsible for the most extravagant productions (move over, Cirque du Soleil). Best of all, these natural phenomena are on the house, courtesy of Mother Nature.
Firefly Trees, Papua New Guinea: At locations across Southeast Asia—from India and Malaysia to Papua New Guinea—fireflies congregate in "display" trees and bushes along mangrove-lined rivers where they breed, synchronizing their flashes for all to see.