An island in the middle of a lake, in the middle of a volcano, in the middle of a bigger lake, in the middle of a bigger island, in an archipelago, in the Pacific Ocean.

The air force base preserves its scars from the Japanese attack on Pearl Harbor.

This iconic clock tower is the largest in the Philippines.

After spending more than a century on the ocean floor, this shipwrecked column is finally resting atop solid ground.

The colorful, smiling concrete silos of Vancouver.

This Costa Rican chapel is the most metal church in the world, literally.

An important Mayan religious and trading center dating back to 200 BC.

These enigmatic ruins continue to vex archaeologists.

A small collection of iguana-infested ruins hides amid Cancún's bustling hotel zone.

One of Mexico's least-visited archaeological sites is tucked away inside a theme park.

A magical sinkhole on the Yucatán Peninsula is adorned with mini waterfalls and hanging vines.

No telescopes, no power, no gift shop: The Observatory of Chichen Itza, one of the world's oldest observatories, takes astronomy back to basics.

Every equinox this Maya pyramid puts on a spooky ancient light show.

Clap your hands at the base of the pyramid, and the song of a sacred Mayan bird will echo through the air.

The site where a plot to assassinate Hitler was planned—and its conspirators were executed—is now a powerful memorial to the German resistance during World War II.

One of the world's heaviest musical instruments towers within a popular urban park.

Berlin's natural history museum houses the world's largest mounted dinosaur and the late beloved polar bear Knut.

A memorial in the Tiergarten is a reminder of the suffering inflicted on homosexuals by the Nazi regime.

Tiny memorials honor individual victims of the Holocaust.

Thousands of coffin-like pillars make up this controversial Holocaust memorial.

The bunker where Hitler took his own life is hidden under this deliberately ordinary parking lot.

The last remnants of a massive medieval wall that once encompassed the city of Berlin.

This ornate church has survived Nazi and Soviet occupation, including a short stint as a Soviet-era gymnasium and cinema.

The de facto symbol of Copenhagen is this bronze fairytale which cannot seem to keep its head for very long.