The bears may be gone, but their old cages can still be found.

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

The massive machine creates cracking displays of indoor lightning.

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

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

The site of one of the strangest disasters in history—a wave of deadly molasses traveling at 35 mph.

Site of a famous 19th-century transcendentalist utopian community, now abandoned.

One of the now-less-hidden floral gems of the "Emerald Necklace."

19th-century operating theatre in which the use of ether was first demonstrated - plus, a skeleton and a mummy!

The often-overlooked ruins of one of the first buildings designed by famous landscape architect Frederick Olmsted.

Museum dedicated to awful artwork.

Macabre headstones carved with winged skulls, dancing skeletons, and pithy reminders of impending death.

Dim sum, served in a grand old theater.

Ralph Waldo Emerson spent two years living here decades before it became a Frederick Law Olmsted-designed park.

This Boston medical museum features the skull of the famous medical case of Phineas Gage.

Two thousand artifacts from around the world collected by one woman who loved to travel.

A beautiful Victorian-era cemetery, complete with a miniature village.

This remote camping site offers incredible stargazing opportunities.

A large collection of solar and night-time telescopes dot a small area on the Teide mountain range.

A mountaintop space observatory that is certified dark.

Climb to the top of this spiritual tower, and you'll be rewarded with spectacular views.

The largest self-built castle in the U.S., six decades in the making.

An abandoned sawmill from more than 134 years ago stands testament to the ambition of one man.

Located in the world's highest-altitude Dark Sky Community, this observatory welcomes amateur and professional astronomers alike.