A domestic robotic system comprising: a robot having a payload for carrying out a domestic task within a working area and a plurality of sensors (S A1 -S A6, S B1, S B2,S 1, S 2), including one or more local environment sensors (S A1 -S A6, S 1, S 2) that are configured to receive signals from exterior sources local to the robot; data storage, operable to store boundary information that defines the path of a predetermined boundary for the working area, within which the robot is permitted to move; the system characterized in: the robot being programmed to operate in at least the following two modes: (i) a reference trail recording mode, wherein: the robot moves along a reference trail while receiving sensor information from said sensors (S A1 -S A6, S B1, S B2,S 1, S 2), the path of said reference trail being calculated by the system based on said stored boundary information so as to be spaced apart from the path of said predetermined boundary; the system stores, for each of a first plurality of points (105a-105e) along said reference trail, corresponding reference trail information, said reference trail information being derived from said sensor information corresponding to said first plurality of points; (ii) a navigation mode, wherein the robot moves within the working area, and navigates by: receiving current sensor information from said sensors (S A1 -S A6, S B1, S B2,S 1, S 2); when in the vicinity of said reference trail, comparing said current sensor information with said reference trail information in order to determine its current position. a robot having a payload for carrying out a domestic task within a working area and a plurality of sensors (S A1 -S A6, S B1, S B2,S 1, S 2), including one or more local environment sensors (S A1 -S A6, S 1, S 2) that are configured to receive signals from exterior sources local to the robot; data storage, operable to store boundary information that defines the path of a predetermined boundary for the working area, within which the robot is permitted to move; the system characterized in: the robot being programmed to operate in at least the following two modes: (i) a reference trail recording mode, wherein: the robot moves along a reference trail while receiving sensor information from said sensors (S A1 -S A6, S B1, S B2,S 1, S 2), the path of said reference trail being calculated by the system based on said stored boundary information so as to be spaced apart from the path of said predetermined boundary; the system stores, for each of a first plurality of points (105a-105e) along said reference trail, corresponding reference trail information, said reference trail information being derived from said sensor information corresponding to said first plurality of points; (ii) a navigation mode, wherein the robot moves within the working area, and navigates by: receiving current sensor information from said sensors (S A1 -S A6, S B1, S B2,S 1, S 2); when in the vicinity of said reference trail, comparing said current sensor information with said reference trail information in order to determine its current position. (i) a reference trail recording mode, wherein: the robot moves along a reference trail while receiving sensor information from said sensors (S A1 -S A6, S B1, S B2,S 1, S 2), the path of said reference trail being calculated by the system based on said stored boundary information so as to be spaced apart from the path of said predetermined boundary; the system stores, for each of a first plurality of points (105a-105e) along said reference trail, corresponding reference trail information, said reference trail information being derived from said sensor information corresponding to said first plurality of points; the robot moves along a reference trail while receiving sensor information from said sensors (S A1 -S A6, S B1, S B2,S 1, S 2), the path of said reference trail being calculated by the system based on said stored boundary information so as to be spaced apart from the path of said predetermined boundary; the system stores, for each of a first plurality of points (105a-105e) along said reference trail, corresponding reference trail information, said reference trail information being derived from said sensor information corresponding to said first plurality of points; (ii) a navigation mode, wherein the robot moves within the working area, and navigates by: receiving current sensor information from said sensors (S A1 -S A6, S B1, S B2,S 1, S 2); when in the vicinity of said reference trail, comparing said current sensor information with said reference trail information in order to determine its current position. receiving current sensor information from said sensors (S A1 -S A6, S B1, S B2,S 1, S 2); when in the vicinity of said reference trail, comparing said current sensor information with said reference trail information in order to determine its current position.