The highest pedestrian bridge in Singapore looks like a series of undulating waves rising between two public parks.

Rare recess caves fill this unbelievably beautiful Ohio park.

A remote hill on a stretch of country road where the laws of physics are defied... or so it seems.

This unique bridge curls up like a caterpillar to let boats pass and then unfurls again to span a small canal.

A working model of the entire San Francisco Bay and much of the Sacramento River Delta, complete with regular tides that change every 14 minutes.

These magnificently sculpted tombs represent Spain's own legendary version of "Romeo and Juliet."

These fantastically named natural pools look like something out of a Scottish myth.

A pair of slides and a tree-lined stair corridor have been an urban oasis for nearly 40 years.

Bring your own cardboard to the slippery slopes of concrete hidden in a neighborhood park.

Spend a day hanging out with domesticated Russian foxes.

The largest permanent Monopoly board makes one of the longest games even bigger.

A clerical error gave rise to this imaginary micronation in the southwestern corner of Estonia.

Started nearly 100 years ago, this science experiment just keeps on going, ever so slowly.

The labyrinthine storm tunnels beneath the city of Melbourne are ruled by a band of urban explorers.

An abandoned jewel of a ballroom on the top floor of Australia’s busiest rail station echoes with the sounds of a bygone era.

A wonder of natural limestone formations etched by millions of years of natural interaction between rainfall and rock and air.

This rickety old shed hides a trove of secondhand literary treasures.

The Australian terminal of the Pacific Cable that linked the continent to North America.

This historic Australian bridge was built by convicts with giant stone spikes to prevent cattle from falling off the sides.

One of the best beaches in the entire world.

Granite rocks that concentrate waves into powerful jets.

A granite waterfall cascading down is one of the highest multi-tiered falls in the state.

A beautiful, but toxic, lake formed by mining.

A huge maze complex and whimsical miniature village in Tasmania.