Pakistan, June 9 -- Just before dawn, when the inky sky is beginning to lighten, the hordes arrive. Coaches cram the streets, torch-wielding guides shepherd tourists through dusty car parks; queues form, selfie sticks vie for space, and the crowd elbows into position for that perfect Wat shot.

Welcome to the pandemonium that is sunrise at Angkor. As one of the most important archaeological sites in South-East Asia, the 159 sq mile UNESCO site is not only the largest religious complex in the world, but also arguably, the busiest.

Its three top attractions: Angkor Wat, Bayon and Ta Prohm - dating from the ninth to the 15th century - draw more than 2.5 million people a year. Successfully tackling the 'Big Three' in one day - and missing th...