Thousands of tourists flocked to watch the spectacular spring equinox at the Angkor Wat temple in Cambodia.

More than 10,000 people - many holding their camera phones aloft - visited the historic tourist Khmer site in Siem Reap to admire the celestial phenomenon at sunrise on March 21.

Breathtaking footage shows the sun cresting the majestic central lotus spire of Angkor Wat, marking the beginning of spring in the northern hemisphere.

Incredibly, the ancient Khmer people are believed to have built the worship site with such precision so that the sun appeared to be like a ball resting on the temple point during the equinox, making it a spiritually significant day.

Local officials estimated that around 7,500 Cambodian locals and 2,500 international tourists trooped to the site before dawn to witness the sunrise.

Cambodian beauty queen Sovattey Sary said: 'This was an experience like never before. I am in awe of the richness and beauty of my country. The ancient temples are spectacular.'

An equinox is an astronomical event in which the sun is directly above the Earth's equator, resulting in equal durations of day and night.

Equinoxes occur twice yearly - the spring or vernal equinox in March, and the autumnal equinox in September.

At the Angkor Wat, the phenomenon is marked by the sunrise aligning perfectly with the temple's central tower.

The Khmer Empire remains one of the world's greatest civilisations. It covered much of what is present-day Southeast Asia, and its culture continues to be imitated by neighbours in Thailand, Laos and Myanmar.