A geological mystery on Camelback Mountain.

Twelve grave-faced marble angels guard the emperor's tomb at Les Invalides.

Medieval museum built over Roman baths that features famous tapestries of a lady and a unicorn.

This statue was given to France by the United States to commemorate the centennial of the French Revolution.

A small 19th-century graveyard tucked away in the middle of a suburban neighborhood.

Once America's tallest structure, now a Baltimore landmark.

This bug-eyed water wheel uses the power of the Sun to clean up Baltimore Harbor.

A daily replay of the experiment that proved the rotation of the Earth.

This elaborate towering structure was once famed for its revolutionary height.

The site where Poe "in great distress, and ... in need of immediate assistance" likely died.

This historic lighthouse was well known for the large number of women who served as its keeper.

A museum dedicated to exhibiting remarkable outsider art.

The Decoy Capital of the World.

Baltimore's classic clock tower was once topped by a rotating, 20-ton medicine bottle.

The design of this historic domed church was influenced by Thomas Jefferson and intended as a statement of religious freedom.

City law dictates that this mountaintop cathedral containing the heart of a saint is to remain the tallest building in town.

This lovely, if imposing, piece of Canadian gothic is possibly the most photographed hotel in the world.

A grand Gothic Revival basilica with stained glass depictions of Montreal's religious history has only one soul resting in its crypt.

A 200-year-old bar with a cheeky name claims to have served Edgar Allan Poe his final drink.

A collection of artifacts from Maryland's maritime past.

The slate extracted from these Pennsylvania quarries was once hailed as the finest in the world.

This English-inspired Maryland garden is home to acres of opulent plant life including bushes shaped into an entire fox hunt.