The gorgeous library at Trinity College is home to remarkable treasures of Irish identity.

This 19th-century prison once held Irish revolutionary Constance Markievicz, writer Frank O’Connor, and a nine-year-old pickpocket.

This Arizona observatory is famous for investigations into Martian life, and as the place humans first spotted Pluto.

Ancient pueblos built into the base of a natural canyon wall.

This historic national park is covered in the stunning ruins of red rock pueblos.

This garden boasts a magnificent collection of orchids and a spectacular view of the surrounding valley.

This museum of Hawaiian and Polynesian culture is the legacy of the last descendant of the Kamehameha Dynasty.

The first plantation museum in the United States to focus on the lives of enslaved people.

One man's swirling six-acre monument of stone.

A once grand hotel is being retaken by the wilderness it once capitalized on.

The Hudson River School comes alive at this palatial estate.

The abandoned ruins of America's first private zoo are open for exploration in the Catskills.

An abandoned dollhouse factory.

The only intersection in America where the buildings on all four corners were built pre-Revolutionary War.

"A hideous albatross in the Hudson River Valley."

The oldest continuously inhabited street in America.

This stone gatehouse was once the entrance to a historic mountain resort, and it had a cameo in a cheesy cult horror movie.

An architectural marvel that combines Gothic architecture with Indian elements.

Tucked in Mumbai’s wealthiest neighborhood is one of the city’s oldest and most sacred sites: a temple complex believed to house the waters of the Ganges.

These colorful staircases can be found around Goa’s capital.

In the heart of Panaji, a monument to the pioneer of modern hypnotism.

Many Hindus make the long pilgrimage to this holy city to have their remains burned on the banks of the Ganges River.

Known as the leaning temple, the sacred structure has somehow developed a severe nine-degree slant.

This magnificent 18th-century hall consists of a maze of nearly a thousand interconnected passages.