**NOTE (you can click on the above photos to blow them up to full size)**
If you are visiting the city of Nakhon Ratchasima in Isaan, I would highly recommend a visit to the Korat Zoo. The zoo is located about 20 minutes south of Nakhon Ratchasima (also known locally as Korat) and is accessible via Highway 304 from Highway 2 or Highway 24. Highway 2 runs in a northeastern direction from Bangkok to Khon Kaen, with Nakhon Ratchasima about midway. So if you were coming from Bangkok, you would take Highway 2 north, then south on Highway 304 to reach the zoo. Highway 24 runs east from Nakhon Ratchasima, so if you were coming from say Cambodia, you would want to head west on Highway 24, then take Highway 304 north to reach the zoo. There are signs in English for the zoo once you are on Highway 304.
In 2007, the entrance fee was 50 baht for Thai and 100 baht for foreigners (that’s about $3 American). The zoo has a very cool feature which you can see in the attached photo – a tram system. You start off from the visitor center in one of these vehicles, then you simply jump off when you want to visit a particular exhibit. If you are not interested in say the snake exhibit, just stay on the tram until it reaches an exhibit you are interested in. The trams run every 10 minutes or so, so it’s never a long wait until the next one arrives to take you onto the next destination. I visited the zoo twice and both times the tram system was very efficient.
The layout of the park and the exhibits are well designed and with the trams you get a real Jurassic Park feel to the place! The bird exhibits were particularly impressive. There are snack shacks along the way and of course souvenir shops. The zoo closes at 5pm. The last time I was there in fall 2007 they were building new exhibits so I think the zoo will likely expand. Unfortunately, there isn’t a lot of information in English available about it, the website is in Thai only.
The gift shop has a lot of nice souvenirs including hats and polo shirts with the Korat Zoo name. When I was there on a Wednesday, the gift shop had closed early, before 5pm I believe it was, but they were willing to open it back up for me when I said I wanted to buy a polo shirt 
A word to the wise, be prepared that if you must use the toilet, there is no toilet paper provided in the stalls. You must purchase it from one of the gift shops. When you enter the zoo, they will give you a map of the zoo so you can identify at that time where the facilities are. 
To tour the zoo expect about 2-4 hours depending upon how much of everything you want to see. You should allow at least 2 hours but if you have 4 hours to spare there certainly is enough exhibits to keep you busy. And the landscaping of the zoo is very relaxing, so you will likely want to allot some time to simply sit on one of the benches and relax and enjoy the green surroundings.
