A miniature train-ride through Slovenia's largest cave system.

Castle and secret tunnel withstood a siege until its owner was killed by the Holy Roman Empire, while sitting on the toilet.

A secluded, little-known temple hidden amid the dense jungle.

A small 12th-century temple surrounded by waters believed to have curative properties.

This Cambodian riverbed is covered in ancient Hindu carvings both above and below the waters.

A former French military respite turned jungle tourism hotspot.

A battle between nature and architecture in the Cambodian jungle.

Ho Chi Minh's perfectly preserved body has been on display here since 1975.

The notorious "Hanoi Hilton" where Vietnamese colonial subjects and later American POWs, including John McCain, were imprisoned.

Many Hindus make the long pilgrimage to this holy city to have their remains burned on the banks of the Ganges River.

This opulent 16th-century Maharaja’s palace is a unique mix of Hindu and Muslim designs.

The 953 windows undoubtedly make this the world's most beautiful screened porch.

Sacred Indian temple that’s all monkey business.

The world's second-largest sundial, made entirely out of stone.

Thousands of exquisitely carved stone water storage wells, hundreds of stone steps fill this exquisite medieval stepwell.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.

The picturesque birthplace of Icelandic democracy is drenched in the blood of its brutal past.

This beautiful, historic church looks like something out of a simpler past.

This stunning concert hall has become a symbol of Iceland's national recovery.

This valley of hot springs and boiling mud pots is home to the record-holding "Geysir," which originated the English word.

If a glacial river suddenly diving into a sheer chasm via a dramatic, multi-stage waterfall isn't peak Iceland, it's certainly close.

One of the tallest buildings in Iceland, and perhaps, the most visually impressive.

This eye-popping Icelandic crater lake is surrounded by red volcanic rock.

This centuries-old gothic monster has been converted into a sprawling, glossy bookstore.