Wat Phnom illuminated at night. Wat Phnom is one of the most important pagodas in Phnom Penh. Built in 1373,it stands at 27 metres and is the tallest religious structure in the city. Built on an artificial hill by the wealthy widow Daun Chi Penh after a great flood washed statues of Buddha downstream, it has since been renovated. There have been many additions to the original shrines over the cen.