A method of establishing an area of confinement and an autonomous robot for performing a task within the area of confinement. In one aspect, the invention can be a method of defining an area of confinement comprising: positioning the autonomous robot at a starting point P.sub.0 and recording the starting point P.sub.0 as a reference point within a memory device; moving the autonomous robot from the starting point P.sub.0 about a perimeter of the area of confinement, wherein said movement of the autonomous robot is controlled by a user; continuously tracking location of the autonomous robot relative to the reference point P.sub.0 during said movement using a distance-traveled measuring mechanism and a directional indicating instrument; recording the tracked location as a map in the memory device; and upon detecting that the map includes a closed-geometry, defining the closed-geometry as the perimeter of the area of confinement within the memory device.