A church of bones, decorated with 40,000 human skeletons.

The first museum in the world devoted to sexual gadgetry.

These spectacular ruins were built by Spanish padres in the 17th century.

Of the many Jesuit missions in South America, this complex is one of the best preserved.

An abandoned network of military bunkers and tunnels open for anyone willing to descend into the darkness.

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

A 131-year-old wunderkammer of Texas history.

The tree is thought to be the oldest oak in Texas and was once crowned state champion for its monumental size.

A tower that pays homage to local sailors who perished under the waves.

An unrealized Taoist palace left abandoned in a Houston suburb.

A taste of Middle Earth, in the middle of the Bayou City.

A former waterfront market is now in the center of town due to some interesting Boston engineering.

This monument on Breed's Hill proves that one of the most famous battles of the Revolutionary War is misnamed.

The site of Paul Revere's historic two lantern warning.

The American Revolution was galvanized into serious action due to the tragic clash with British soldiers that occurred at this location.

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

This peculiar lake of pitch is so thick and viscous that one can walk on its surface.

A series of waterfalls so massive they straddle the border of Argentina and Brazil.

The fighters and conspirators that won independence for Paraguay held secret meetings at this historic house.

As one of the world's largest hydroelectric dams this plant took two countries to get built.

Five sultans and their families rest in eternal splendor, teeming with overlooked beauty and drama.

Legend says if you stick your thumb in the hole and it gets wet your wish will be granted.

A marvel of Byzantine engineering under the streets of Istanbul.

This everlasting lightning storm may be the world's largest generator of ozone.