Ancient City
Has scaled replicas of buildings from all over Thailand and is interesting to cycle round. To get there independently from Bangkok, take the Skytrain to On Nut. Then a 511 air conditioned bus ask to be told when to get off for Muang Boran. Then you take a no. 36 pickup truck bus 'songthaew' 8 or 9 baht, the rest of the way ask to be told when you're there or keep looking left across the canal. That's an hour or more on the buses. A taxi ride from On Nut Skytrain station costs around 170 baht.
Crocodile Farm & Zoo
This place is the largest crocodile farm in the world and is certainly worth visiting, if not just to see the crocodile wrestling and acrobat elephant shows. There is an education and research center for the preservation of wildlife and also a dinosaur museum. A fun day out for all the family.