A 19th-century subterranean reservoir repurposed as a contemporary art cave.

Nordic giants resurrected from the sea and restored to their former greatness.

This triumphal 16th-century arched gateway leads to the oldest street in Palermo.

Iconic red and white plaques show the creative names invented to navigate the city streets.

Ice cream stand, snack bar, and time capsule of milk conveyance.

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

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

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

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

The former site of an all-but-forgotten colonial landmark is now remembered by an often overlooked bas relief.

Each August, one of the largest religious (and food) celebrations in the country is held in Boston.

Statue commemorating the use of ether in anesthesia.

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

Mrs. Mallard and her brood are a beloved fixture in Boston Public Garden.

A men’s restroom became a sandwich shop.

It took 82 years and four different plaques to finally get the story right.

A backdoor to Machu Picchu that only the most foolhardy infiltrator would attempt to breach.

Science meets wall art to highlight the beauty of famous mathematical equations.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The early data processor factory founded in Washington for the 1890 U.S. Census went on to become IBM.

A portal into the bricked up canal that runs through the heart of Washington D.C.

Long-abandoned trolley tunnels just a mile away from the White House are turning into an art space.

A line of blue paint marks the route of the inaugural parade.

The final resting place of soldiers' loyal canine companions.