A striking symbol of the Bulgarian capital.

"Holy Wisdom" overlooks the city that became its namesake.

Climb inside an iron crystal magnified 165 billion times its normal size.

The place where World War I began.

The massive machine creates cracking displays of indoor lightning.

Berthed at the Charlestown Navy Yard in Boston, "Old Ironsides" is the oldest commissioned warship still afloat.

These secluded and abandoned anti-aircraft defenses have become one the most scenic viewpoints in Barcelona.

Construction of Barcelona’s iconic (but controversial) church was finally completed in 2026—a century after the death of its architect.

The oldest amusement park in the world has been providing a nice spot to have some fun since the 1500s.

This sublime architectural marvel is a rare example of an expressionist church.

The headquarters of the Mahanikai school of Buddhism, Thailand's largest monastic order.

This elephant kraal is the only one remaining in Thailand, dating back to the 16th century when these massive mammals were integral players in war and trade.

Single runway interrupted by a busy road that cuts across its middle.

This quaint Spanish village agreed to be painted blue as a marketing stunt but found that they preferred it that way.

Three bridges and one giant canyon make up this fantastic Spanish settlement.

Spanning the El Chorro gorge, this pathway used to be one of the most dangerous crossings in the world.

Unusual building appears to be haphazardly built from randomly piled bricks.

Ancient rock-hewn town that witnessed key events of Georgian history.

These Stalin-era industrial 'death traps' hang lifeless above the city

Small church on top of a huge rock column.

Fortified homes of highland warriors that are still in use today.

Despite being tiny and rural this Georgian airport looks like a sci-fi boondoggle.

This neon lit Georgian cave claims to hold the boulder Prometheus was chained to.

Tower with a double-helix spiral, adorned with letters of the Georgian alphabet.