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

A king's pet, a pope's gift, an artist's inspiration, and a tragic shipwreck.

This unreal Portuguese palace looks as though it's made from a pile of different castles.

A 16th century chapel decorated with bones, skulls, and entire bodies hanging from the wall.

This eccentrically decorated palace is replete with grottoes, fountains, tunnels, and caves.

Intricate wood carvings on an island in Siberia.

The gorgeous entrances into the city's underbelly look more like grand halls than subway stops.

This building holds the embalmed remains of the leader of the Bolshevik Revolution.

The home of half the world's population of critically endangered mountain gorillas.

Where the White Nile River dramatically cascades between Lake Kyoga and Lake Albert in Uganda.

The clock tower is a prominent landmark in the bustling commercial hub in the heart of Jodhpur, showcasing intricate architecture and cultural significance.

An ancient wall in the shadows of the Amber Castle.

Legend has it a commoner volunteered to be buried alive in the foundation so that the great fortress could be built.

Hidden in the rain-forests of Arunachal Pradesh in Northeast India lies the village of Ziro, home to the Apatanis.

The largest freshwater lake in northeast India is also the only floating national park in the world.

Ornate, dome-topped cenotaphs fill this royal crematorium.

This opulent 16th-century Maharaja’s palace is a unique mix of Hindu and Muslim designs.

An imperial fortress city that incorporated cultural elements from the entire Mughal empire, only to be abandoned the year it was finished.

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

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

Hidden in the shadow of a rocky fortress is one concubine’s long-forgotten legacy.

The world's second-largest sundial, made entirely out of stone.

More than half of this Indian palace is drowned but it looks all the more spectacular for it.

The 953 windows undoubtedly make this the world's most beautiful screened porch.