Ha Long Bay's "Cave of Surprises" houses a popular phallic rock formation.

Monument to a brutal, ineffectual US bombing campaign and a sobering reminder of the human cost of the Vietnam War.

These crumbling towers are some of the last remnants of a centuries-old Vietnamese culture.

A nightmare for the claustrophobic lies hidden in Southeast Asia.

Tibetan-influenced mountain fortress in Northern Pakistan.

The place of worship for Zoroastrians, Mumbai's Parsi fire temples use fire and ash for purification.

The site of an atrocity that would be used to justify Britain’s conquest of India.

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

Scholar, adventurer, saint, and instigator of the Goa Inquisition.

There are millions of temples in India, but only one prominent temple dedicated to the Hindu creator god.

Fifteen Jodhpur queens left their handprints before going to their fiery death.

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

An ancient iron pillar in Delhi that seems to be rustproof.

This 17th-century mausoleum is topped with an acoustic marvel.

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.

Modest by day, illuminated majestically at sunset.

A blooming house of worship for the masses.

An extraordinary "City of Caves" carved from solid stone.

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

Rock-cut cave complex filled with ancient Buddhist artwork.

The remains of what was, not so long ago, the world's largest city.

This complex of vertically-excavated Buddhist, Jain, and Hindu monolithic temples in India's Maharashtra providence illustrates a spirit of tolerance characteristic of ancient India.

Once an indicator of social class, the color blue has come to define this city on the edge of the Thar Desert.