I live in the countryside about an hour from Prague, once you get out of the cities, there are LOTS of places to wheel. I have a lightly modded YJ crawler and I'm 5 minutes from all kinds of fun logging roads and wilderness areas. They have several gatherings here in the summers, a few in the winters. I've only gone to two: 1) a Landcruiser Party (mostly modified Landies, but more than a few Jeeps) and 2) a Jeep club event complete with rock bands and food and some SERIOUSLY modded rides there. If you have never seen an 8x8 Tatra go up a 70 degree face of rock you're in for a treat.
One thing I've learned here is that "tread lightly" goes a long ways, the Czechs tend to bomb around a lot harder than I would, and I've never had any complaints from anybody where I've been wheeling. I even got stuck in some deep mud driving solo on a logging road. I don't have a winch, and was preparing to "Hi-Lift-tug" my way out when 4 friendly loggers came over, jumped knee deep into the mud and pushed me enough to get out.
Ramble ramble... Look me up when you get here if you want to go wheeling somewhere. My rig's not exactly highway legal yet (working on it...) so I'm a little limited on where I can go (my tow rig's back in the states) but if you're anywhere near Prague, there are some fun muddy spots to play in, while these 'gatherings' tend to rent out gravel quarries for a weekend etc depending on what you're into.