Try the BattleGround Plugin, it allows you to create an arena for any mini-game (CTF, spleef, paintball, ect..) then allows a player to enter that arena with a command when there are ppl ready to use that arena
can you give me link for this plugin,please can you give me example,please? why? EDIT by Moderator: merged posts, please use the edit button instead of double posting.
http://google.com?q=BattleGround+Bukkit I can't to be honest, you asked for an arena, but you never said for what.
Uh, to my experiences try using citizens 2 and builders plugins, then go on the citizen plugin forums and find a schematic and upload that using builder and it should be begin building