Isaan, Thailand's north-east region, is an often overlooked part of the country. There's no coastline, so there are no beaches to draw those seeking sand and sea. Isaan, however, is a multicultural area where Laos, Cambodia and Thailand meet, and has a rich history. Isaan is mainly an agricultural
Northern Isaan The parks of Loei, Ban Chiang, Nong Khai, Wat Phra That Phanom, etc.
Central Isaan Also highway from Bangkok ends here in Khon Kaen
Southern Isaan Centred Ratchasima, the Mun River Basin is home to Khao Yai National Park and the beautiful Khmer architecture of Phanom Rung and

Cities

How to get there?

By Plane
Domestic flight from Bangkok to The main airport to the cities of Khon Kaen, Nakhon Phanom, Sakon Nakhon, Ubon Ratchathani and Udon Thani can be reached by plane from Bangkok on both of Thai Airways and Air Asia

By Bus
From Mo-Chit station Bangkok go to major in Cities.

By Train
From Hua-Lamphong railway station Bangkok to Ubon Ratchathani (Pass Nakhon Ratchasima, Buriram, Surin, Si Saket and other stations along the way and Nong Khai(via Khon Kaen, Udon Thani, etc)

Information more at : http://www.tourismthailand.org