This subterranean oyster house has been the pearl of Grand Central Station since 1913.

A dark patch of the ceiling at Grand Central Terminal which was not restored is still stained brown by tobacco.

An extraordinary mix of Phoenician, Roman, early Christian, and Byzantine ruins beautifully set overlooking the Mediterranean.

This statue is the only female representation of Rome's "talking statues."

One of several skulls claiming to belong to the beheaded St. John the Baptist is on display at this Roman church.

A forgotten "city of water" underneath the famous Trevi district.

This hidden alley near the location of Rome's first theater was the site of a curious miracle.

This park on the outskirts of Rome boasts two ancient Roman aqueducts and a medieval tower.

This curious, round temple is the oldest still-standing marble building in Rome.

More sculpture than building, this architecturally significant temple was built on the spot of Saint Peter's crucifixion.

The engineering wonder and pleasure dome of a much-maligned emperor still holds undiscovered secrets.

The crypts of Capuchin friars decorated with the bones of over 4,000 friars, including an entire "crypt of pelvises."

Elevated freight railway turned wildly successful urban park.

Amid the bustle and noise of the Financial District hides a secluded garden oasis above the city streets.

Eat the ultimate iteration of Portugal's most beloved pastry.

This Industrial Age architectural and engineering gem helps visitors and residents alike traverse Lisbon, “The City of Seven Hills.”

Legend says this is actually a heartbroken prince waiting for his true love's kiss.

After the famous composer died in Paris, his sister snuck his heart out of the country to honor his wish that it be buried in their native country.

Hundreds of notes give thanks to the patron saint of lost causes.

The giant statue and its model solar system honor the native Pole who declared that the Earth revolves around the Sun.

This colorful statue welcomes visitors to a Barcelona park.

Spain's unique Mosque-Cathedral has been a place of worship for both Muslims and Christians throughout its history.

Perhaps the most spectacular grotto along the Algarve coastline.

This restored Portuguese cafe may well be the most beautiful place in the world to grab a Big Mac.