In the Khmer language, Phnom means hill. Phnom Chisor is a small hill 42km (26mi) outside of Phnom Penh. On top of that hill is an ancient temple dedicated to Shiva and Vishnu. The Angkorian era temple was built under King Suryavarman I during a time when the hill was known Suryaparvata - or 'Mountain of the Sun God.'
It was quite sunny when I visited, illuminating the spectacular ruins. The distortion you see is typical of a fisheye lens, which is what I used to take the photo. Honestly, it was so sunny at hot at the time, that I recall just standing around taking a few photos was quite an ill conceived plan.
I really enjoy temple hopping through ancient ruins like this one. I find it fascinating and beautiful all at the same time. Even though November through February is the coolest time of the year to visit, the weather goes from unbearably hot to just bearably hot. Don't forget the sunscreen.