A method for mapping a multiple-floor structure includes building a plurality of maps that includes one map for each of at least two of the floors, detecting a set of anchor points, where the set of anchor points includes at least one anchor point on each of the maps, linking the anchor points to produce a set of linked anchor points, and aligning the maps around the set of linked anchor points to produce a set of aligned maps. A method for mapping a structure using a single robot includes generating, by the robot, a first map at a first point in time, storing the first map, generating, by the same robot, a second map at a second point in time subsequent to the first point in time, and aggregating the first map and the second map to produce an aggregated map.