One man's dream has turned into this naturally growing chapel made of almost nothing but trees.

Anyone wanting to know what a dwarven mine sounds like need only visit the tunnels of this New Zealand artillery compound.

The yawning remains of a complex naval fortress still haunt this Australian shore.

An ancient rock engraving shows Aboriginals used their advanced knowledge of the stars to hunt and gather.

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

This dangerous-looking suspension bridge may have been too unstable to remain open.

A series of waterfalls and pools that flow through the 'Ohe'o Gulch and into the ocean.

The superstar of Cold War nuclear bunkers has been featured in countless films but is now barely operational.

Isak Heartstone, a 15-foot wooden troll made out of recycled materials.

Air Force Academy Chapel made of 100 identical tetrahedrons works to inspire those of all religions.

These decaying bridges 1,000 feet high are a reminder of the skill it took to cross the Colorado Rockies by rail.

A spring-fed pool so deep it's used for scuba diving as well as swimming.

Minimalist modern art on a repurposed military base in rural Texas.

A mother's mourning for her lost son is remembered in this small park embedded with his memory.

Three hundred years of preserved Spanish colonial history in San Antonio.

A medieval castle in the middle of rural Texas.

Football field-sized microalgae production tanks on the Hawaiian coast create a stunning view from space.

A true treehouse near Hawai'i Volcanoes National Park.