More commonly known to foreigners as the River of a Thousand Lingas, this is an area of riverbed carvings similar to Phnom Kulen, but more peaceful. Kobal Spien is about a half-hour walk up a pleasant path shaded by jungle to where the carvings begin. It is sensible although not entirely necessary to get someone to guide you who can also tell you about what you are actually seeing. Either way, do not wander off well-trodden paths as there is a serious landmine problem here. The river eventually appears on your left and the first carvings include a large image of Vishnu. As you continue on, you come to an area with several good images of Rama, Lachsme and Hanuman, and further up some lingas. On the way back down there is a path which follows the river and along this stretch are hundreds of lingas, hence the name the River of a Thousand Lingas. These eventually lead to a waterfall with a pool below. Kobal Spien is about 30 km north-east of the Bayon and about 9 km beyond the temple of Banteay Srei along a good dirt road.