This is a man made reservoir just across from the entrance to Banteay Kdei. There are steps going down into the reservoir. Water is here year round. There is actually a trail that goes around the reservoir. I didn’t have time to hike it. Seems like a good activity if you rent a bike. There is also a small village here. They sell drinks, snacks and souvenirs. The children hawk the trinkets quite aggressively. More so than other places around Angkor.