Mobile device configured for determining a position (POS) of the mobile device within buildings, the mobile device comprising: one or more motion sensors being configured for detecting directions and/or distances of a movement (M') of the mobile device ; one or more proximity sensors being configured for detecting characteristics of one or more electromagnetic fields (RWF, MAF); a relative feature spot map establishing module (15; 17) configured for establishing one or more relative feature spot maps (RSM) comprising relative coordinates (xr, yr) of the movement (M') of the mobile device and relative coordinates (xr, yr) of relative feature spots (W', MF', ST', EV'), wherein the establishing of the one or more relative feature spot maps (RSM) is based on the detected directions and/or distances of the movement (M') of the mobile device and based on the detected characteristics of the one or more electromagnetic fields (RWF, MAF); wherein the relative feature spot map establishing module (15; 17) is configured for transmitting the one or more relative feature spot maps (RSM) to an absolute coordinates determining module (16; 18) configured for determining absolute coordinates (xa, ya) of the mobile device ; wherein the absolute coordinates determining module (16; 18) is configured for receiving a plurality of absolute feature spot maps (ASM) from a memory (6; 19), wherein each absolute feature spot map (ASM) of the absolute feature spot maps (ASM) comprises absolute coordinates (xa, ya) of feature spots (W, MF, ST, EV) of one building of the buildings; wherein the absolute coordinates determining module is configured for determining the absolute coordinates (xa, ya) of the position (POS) of the mobile device by determining to which absolute feature spot map (ASM) of the absolute feature spot maps (ASM) the one or more relative feature spot map (RSM) correspond. one or more motion sensors being configured for detecting directions and/or distances of a movement (M') of the mobile device ; one or more proximity sensors being configured for detecting characteristics of one or more electromagnetic fields (RWF, MAF); a relative feature spot map establishing module (15; 17) configured for establishing one or more relative feature spot maps (RSM) comprising relative coordinates (xr, yr) of the movement (M') of the mobile device and relative coordinates (xr, yr) of relative feature spots (W', MF', ST', EV'), wherein the establishing of the one or more relative feature spot maps (RSM) is based on the detected directions and/or distances of the movement (M') of the mobile device and based on the detected characteristics of the one or more electromagnetic fields (RWF, MAF); wherein the relative feature spot map establishing module (15; 17) is configured for transmitting the one or more relative feature spot maps (RSM) to an absolute coordinates determining module (16; 18) configured for determining absolute coordinates (xa, ya) of the mobile device ; wherein the absolute coordinates determining module (16; 18) is configured for receiving a plurality of absolute feature spot maps (ASM) from a memory (6; 19), wherein each absolute feature spot map (ASM) of the absolute feature spot maps (ASM) comprises absolute coordinates (xa, ya) of feature spots (W, MF, ST, EV) of one building of the buildings; wherein the absolute coordinates determining module is configured for determining the absolute coordinates (xa, ya) of the position (POS) of the mobile device by determining to which absolute feature spot map (ASM) of the absolute feature spot maps (ASM) the one or more relative feature spot map (RSM) correspond. <EOS>