It's kinda like towney protections, but the only people on the server that can access WorldGUard are the Admins, meaning THEY are the ones that protected that mountain for whatever reason.
IF it wasnt WG'd I was going to start my tower complex there, lol The protections on it were all that stopped me back in my early scouting. It's the perfect mountain to carve a base out of....guess one of the admins had the same thought XD
Though I'm surprised you are just now noticing it, it's not a new occurance. That mountain has been protected since before I moved out there in May. Thats why I thought it was kinda odd when you started building your house, and then what would become Nexan there.