Since there isnt a lot of info about bankso I;ll post some. I was there in the summer of 02 on a backpacking trip. So my info is just about Bulgaria in general.
We started from the ski resort of Borovec which looked ok but not worth the trip. We hiked through to the rila lakes and rila. Then we ended up in Bansko.
Bansko was an awesome town with really cool old buildings that were all being fixed up and turned into "inns" restaurants and bars. It is very cheap to stay. (we payed about 10 bucks a night for one of the nicest hotel rooms that ive ever stayed in.
From there we hiked up into the Pirin mts national park. Which was then being ruined by the upgrade of the ski resort. The skiing did look pretty fun though. I've been wanting to go back and ski there for awhile and I think it may happen this winter.
