Three thousand is a rock under the Mekong River in Ubon Ratchathani Province, Pho Sai caused by vortex erosion become more 3 000 basin, basin. And will appear during the dry season, the water had dried up. The rock would emerge from the water like a mountain middle Mekong River and people called the "Grand Canyon River". Which is this phenomenon will happen since around October - May. After that, there will be a flood to flood wave that sinks to the river.