I loved Kabah. If you're making the trek to Uxmal, you really ought to go here too. The other sites on the Ruta Puuc are good too, but this is the best after Uxmal.
The city's height was around 900 AD but it was settled since 300 BC. The site is right on the road. You can park on the east or west side, but you can only see the ruins on the east side of the road. There is a lot of of work still to be done here. It doesn't take long to see what is open and you can climb around on many parts of it. You can also get closer to the decoration here than anywhere else.