Heavy rural populations farm the extensive mid-levels of this landscape, but the hills and mountains are left fairly pristine. …The striking heart-shaped hill in the upper middle is Phu Kradung, a favorite hiking mountain for young Thais – with restaurants and tented accommodations on the plateau (a 9 km walk). On the left is the Mekong River, which forms some of the border with Laos, and to the lower right are some clay plains with marsh areas, a part of the vast Siamese lowlands which stretch away to Bangkok.