Neighbor is Using Part of Our Property

[nyalaskan]

My question involves real estate located in the State of: Alaska. My husband and I bought a piece of property that we had been renting for a few years. We bought it a year ago. We found out a few months ago when we walked our property line, using the land plat we got from the Title Agency and the stakes that are still in the ground from the survey in 2003 to figure out where the lines were. We discovered a neighbor to the rear has sort of "moved" thier back yard over a bit, and now they have a swing set on our side of the property line. It is in an area of the property line that we have to walk through a bunch of trees to get to, so I am not sure that I care they use this little chunk, but if someone gets hurt, is it possible that we can be held liable if they are on our side of the property line? Because of this, is there a way I can let them use it, but that it is my property and they are to go no further than a certian point, and that if they use that portion of the property it is at thier own risk. The only other thing I can think of is to tell them they need to stay off it and show them the land plat. ????? Not sure what to do.

[nyalaskan]

Also, I was wondering if I have to get a lwayer involved if they think I am wrong, or do I have to have it surveyed again?