Further afield, east of Nakhon Ratchasima, are the ruins of Prasat Phanom Rung which are arguably more impressive than those of Phimai. Again, a 12th-century structure, Phanom Rung is a well preserved Khmer temple complex, its superb architecture being considerably enhanced by a dominant hill-top location which commands panoramic views of the surrounding countryside.

Nearby, at the foot of the hill, are the smaller but picturesque ruins of Prasat Muang Tam. With 10th-century foundations, the temple pre-dates Phanom Rung and although less well preserved, it possesses a romantic atmosphere in its state of abandoned beauty.

The northeast also has its scenic attractions. It may not hold the same spectacular natural beauty which the north and south have in their own different ways, but it does have some decidedly attractive spots.

Most important is Khao Yai National Park, not strictly within I-san but certainly lying on the edge of the region quite close to Korat. It covers 542,000 acres of protected forest, jungle and grassland spread over rolling hills and mountains (the highest peak is 1,328 m above sea level), and supports a comparative wealth of wildlife.

Other notable parks and wildlife preserves in I-san include Phu Kradung National Park in Loei province. This is a table-top plateau covered largely by evergreen forest and is the habitat of a variety of wildlife and some rare species of birds. Magnificent scenery can be further seen at Phu Luang National Park, also in Loei, and at Phu Pan National Park, just south of Nakhon Sakhon.