I have located a spot on the currated map "Elver"
by going to the cyan room, to the swiming part, if you go foward, take a turn and go behind the boat, theres a unpatched ice area, wich alowes players to go and start walking around the illegal areas of the map, AND EVEN BUILD THERE, its a powerfull glich sence it basicaly makes a unraidable base.