Inspired by a piece of concrete, these three pyramid-shaped buildings have been beloved Indianapolis landmarks for over 50 years.

Safely view the Soufrière Hills volcano, which has been erupting since 1995.

A chilling disappearance (and rescue) of a child uncovers a geological mystery.

Covered in tens of thousands of coats of paint, this Indiana attraction holds a world record all its own.

The biggest solar telescope in the world helps reveal the secrets of our sun.

This public square capitalized on a single Eagles reference to bring some life back to an Arizona town.

This 4,000-foot-diameter hole is touted as "the most well known, best preserved meteorite crater on Earth."

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

A reproduction of earth's many biomes.

This abandoned Navy base was transformed into an off-grid alternative living community for thousands of people.

The ghostly remains of an accidental sea.

Archaeological sites and great food inside the island's largest mangrove forest.

This nearly abandoned "company town" is a ghost of Puerto Rico's once-lucrative sugar industry.

A natural swimming pool in the middle of the Carite Forest.

Enjoy the waters of this half-moon-shaped natural pool surrounded by breathtaking scenery.

The short hike is worth the stunning views and crystal blue waters of a secluded beach.

These red and black houses were awarded to the firefighters who saved their city from an enormous blaze.

This rock in the middle of a river in Jayuya contains dozens of Pre-Columbian Taíno petroglyphs.

This museum preserves the heyday of Puerto Rican coffee.

This beachside town is home to a diverse nature reserve, multiple cays, and one of the three bioluminescent bays in Puerto Rico.

The factory for the popular Dumbo location, the Greenpoint shop is a quiet gem.

La Cara del Indio honors the Taíno chief who fought bravely against the Spanish invasion of Puerto Rico.

This colorful gate stands as an entrance to the walled city of Old San Juan.

Invading U.S. troops were first seen from this now-abandoned tower, leading to the Spanish-American War.