The wrong turn!!!!!!
Fun story: Some years ago, a friend and I were driving around the North bay area (north of San Francisco). We didn't know where we were in detail (just the general area), didn't have a satnav or anything, but figured we'd turn around somewhere and head back down the highway. Must've been seven or eight in the evening. Anyhoo, we take some random turn off the freeway so we can turn around - but it doesn't go to one of those junctions, instead it takes us down some random overgrown road. OK, no worries, we'll turn around somewhere further up as soon as we find some space... we keep going, and then we come across a sign:
"PRIVATE PROPERTY. TRESPASSERS WILL BE SHOT. OWNER NOT LIABLE FOR DEATH OR MAIMING"
You better believe we managed better than a 7-point turn to hurry the hell out of there...