This Yellowstone geyser may not shoot as high as the nearby Old Faithful, but it erupts for considerably longer.

One of nature's most well-scheduled phenomenons resides in Wyoming's Yellowstone National Park.

At the time of its completion, it was the tallest dam in the world.

Amsterdam's narrowest house facade is a monument to 17th-century tax evasion.

A Dutch passageway's artistic, aquatic-themed makeover pays tribute to the capital city's famed waterways.

One of Amsterdam's narrowest houses is located right across the canal from its widest.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

Former headquarters of the KGB.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

Underground monastery and fortress.

Take respite inside this jaw-dropping church while climbing the volcano where Georgia's Prometheus was once chained.

A cylinder monument with a spectacular vista commemorates a friendship that some say never existed.

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

A literally moving statue of stacked metal giants just continually trying (and failing) to find love.

Fast food feels like fine dining at this award-winning modern Georgian building.

This architecturally eclectic fortress witnessed centuries of bloody turmoil, including the massacre of its ruling clan.

You'll find just about anything in this funky Tbilisi flea market.

The charmingly disheveled clock tower of Tbilisi's puppet theater.

A cluster of historic bathhouses built on the famed hot springs that gave the Georgian capital its name.

A rugged lava field dotted with molds of the ancient pines that were growing when the volcano erupted.

This Upstate New York park squeezes a lot of history into its two-acre triangular space.

Why have you never heard of the second most popular tourist site in New York?

This abandoned ironworks was once the most important military supplier in America.

This abandoned factory on the Hudson River once churned out a million bricks a week.