View from the hill to Baan Nongsa 

In this photo, looking east from the sanctuary partway up the mountain, we see the temple's causeway, which runs east-southeast and terminates in two grand barays (excavated reservoirs). The "middle baray," seen end-on in this photo, measures 200x600 meters. Its great length recedes much further into the distance than one can accurately judge here, being approximately equal to the distance from its near bank to the base of the mountain. The north baray (photo left) is wider, and lies due east of the sanctuary. The barays were probably built by Suryavarman II (1113-1150).

One asks why the axis of the temple is south of due east, and why the two barays are situated as they are. The answer lies in astronomy: the barays were designed to reflect the image of the sun, from the middle baray at the vernal equinox, and from the north baray at the summer solistice.