The history and future of cannabis.

The world's oldest Jewish library was founded by Sephardic Jews in 17th century Amsterdam.

This historic Amsterdam bar used to accept sailor's monkeys as payment.

This city square is home to Amsterdam's oldest church and a statue honoring Dutch sex workers.

A hidden church in a hidden courtyard tells the story of the Miracle of Amsterdam.

Three connected pink triangles memorialize persecuted gays and lesbians throughout history.

The home of one of America's most wealthy industrialists is now a historic site that remembers a more decadent time in the country's history.

"A hideous albatross in the Hudson River Valley."

A museum dedicated to the quirky and colorful world created by Springfield's favorite son.

Largest Roman Catholic church in North America.

Founded by the famed children's book artist, this museum spreads an appreciation of the arts through picture books.

This unacceptably tall building was the real reason for Washington, D.C.'s skyscraper ban.

The sculptor was instructed to add “stallion attributes” to the general's bronze mare.

A rotating cast of guys and dolls in front of a Washington, D.C. building.

An overlooked oasis of quiet on the grounds of Washington's monumental basilica.

You can still ride this 100-year-old work of art in Brooklyn's largest public park.

The mass grave of a heroic Revolutionary War regiment sits below an empty lot near the Gowanus Canal.

The one-stop shop for all of your superhero (or evil arch-nemesis) needs.

Volunteer-run library dedicated to exploring five decades of activism history.

A tree that grows parallel to the ground was declared Brooklyn's "crowning curio" by the poet who saved it.

The ballpark in "Pigtown" where the Brooklyn Dodgers made their name was replaced with a huge apartment complex.

A popular European tradition makes its way to the states on one of America's most famous bridges.

A careful eye can find hundreds of dinosaur tracks running along the Connecticut River.

The widow of Benjamin Franklin's brother became the first female newspaper editor in the United States.