They have booby traps (like claymores full of paint hooked to tripwires), quicksand (not deep enough to drown in, but chest deep to hold you if you walk into it so you are an easy target), incoming paint mortars raining down, and more.
Open all year, so if you want to go out in the cold and rain, there are always some lads there. You get the in the morning, pay a few quid, and they make up teams for each area. Then you play out the senario you are in. Either raid an ammo dump, rescue hostages, raid an air strip, and more. It's like Busch Gardens of paint ball the size of the place. All those sites are re-created just like the real thing, and as mentioned, the Irish military trains there.
For 200 euro you can get a few hundred rounds, all yer gear, and kit out. If ye have yer own gear, it only costs like 20 quid for the whole day. Once a team wins, you switch sides and try to defend or attack the same senario you were in. After the bell sounds in a few hours you switch up senarios and try different ones.
Great craic, and if ye go up with a group of 4-8 of yer own people they let you be yer own team and play together. The lad who owned the security company I used to work for took us up a few times a year, we split up in teams of 4-8 and tried all the senarios - he rented the whole place all day and we just blasted each other for hours.
I still have a group of 3 lads, all former military from around the globe, that I go up with on some weekends. I like it best when its dark and rainy. Makes it more realistic and fun. Chest deep in mud crawling through the underbrush trying to creep up on enemy command tents.
Of if yer feeling lazy and don't want to get all dirty (as you will come back covered in mud and what not), just do the terrorist hostage senario and stay inside the office areas waiting for the bastards to bust through the door or windows. Gotta watch for the incoming lads who bring repelling gear in come in through the top floor windows though. They will get you if yer not on the ball.