Nakhon Ratchasima, almost always called Korat, is the big western gate of Isaan. It is not a polished holiday city, and it does not pretend to be one. The appeal is more local: a working Thai city with a moated old centre, a fiercely loved heroine shrine, Khmer traces, night markets, and good onward links to the plateau.
The heart of town is the Thao Suranari Monument, where locals come with incense and garlands for Ya Mo, the woman credited with saving Korat from Lao forces in 1826. Around it are the remains of the old city plan, the Chumphon Gate, food streets, and the ordinary bustle of a provincial capital.
Korat rewards a slow half-day rather than a checklist sprint. Wat Phra Narai Maharat sits on a pond in the old quarter and keeps a Khmer sandstone Vishnu image. Wat Sala Loi, northeast of the centre, is stranger and more memorable: a temple linked to Ya Mo, with a modern ordination hall shaped like a Chinese junk. The small Maha Weerawong National Museum rounds out the story with Buddha images and regional antiquities.
Most foreign travellers use Korat as a base for Phimai, Khao Yai, or deeper Isaan. That is fair, but if you are passing through, do not treat it only as a bus connection. Spend the afternoon around Ya Mo, eat in the old centre, and you get a plain, useful introduction to northeastern Thailand.