The massive, incredibly rare instrument is over 11 feet tall with a range so deep it goes lower than humans can hear.

One of Philadelphia's largest murals resides hidden under this bridge.

The body of St. John Neumann and his collection of hundreds of relics, on display in a Philly church.

Paths are maintained, but trees have taken over plots.

Once the most flame resistant building in the country, the South Carolina Historical Society building was almost burnt down in a fire.

A heartwarming message to those entering and departing Music City from above.

Chewing gum tycoon's memorial lies perched over wife's botanical gardens on Santa Catalina Island.

The stoutest tree in the world.

These biodiverse university gardens form a green oasis amid the urban chaos of Mexico City.

A dark tunnel leads to a striking white crater that seems to be from another planet.

Two waterfalls flow down the cliff faces decorated with rare natural basalt columns.

The ruins of an ancient Mayan city, beautifully preserved and only accessible by boat.

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

An elaborate Mayan city shrouded in alien conspiracy revealed the tomb of Pacal the Great.

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

An Aztec temple, the largest man-made pyramid in the world, sits buried in earth with a Spanish church set on top.

High atop a Mexican rainforest mountain, this ancient pyramid once drew pilgrims countries away.

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.

These azure waters were thought to lead to the Mayan Underworld.

Around 100,000 bodies are buried below the medieval headstones, many of which mark graves with multiple bodies stacked up to 12 deep.