This charming, medieval walled village is Spain's first "book town."

This spot along the 23.5 degree north parallel marks the northern boundary of the tropics.

Dine amidst exotic plants at this former royal greenhouse.

The oldest still-inhabited hill fort in India looks like a magnificent golden sandcastle.

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

This stunning 15th-century royal hill fort preserves the age of chivalry in Rajasthan.

Grab a cuppa at England's first and only domestic tea plantation.

More than 700 species live within this murky marvel of a swamp on California's coast.

Latvia's symbolic mountain-shaped national library is home to millions of cultural tomes.

An ancient octagonal weather station named for the eight Greek gods of wind.

This overlooked museum houses an amazing collection of rare, antique typewriters.

Behind medieval walls in a corner of bustling Palermo is a breathtaking former mosque once inhabited by a wolf-taming hermit.

The ruined doorway is a portal to the building's turbulent and torturous past.

Ireland's most remarkable collection of these curious cone-shaped houses is worth the buzz.

The world’s largest collection of Tiffany glass sits in a warehouse in Queens.

England’s ancient oak tree has such an impressive girth, people have been hosting parties within the hollow trunk for centuries.

A sophisticated astronomical tower built by one of the greatest Persian scholars of the Islamic Golden Age.

This hidden workshop is filled with molds of France's most iconic sculptures.

Taiwan's last Chinese character letterpress preserves the dying art of Chinese character mold making.

A sharp sculpture made of thousands of pieces of jagged glass.

An ancient Viking runestone hidden in plain view in Stockholm's old town.

This 700-year-old structure is one of the most unique architectural and historic monuments in Gdańsk.

This incredible college library is a visual masterpiece of mosaic art. It also looks kind of like a giant boombox.

A spectacular rainbow of stained glass makes the "Pink Mosque" one of the most beautiful in Iran.