Abstract: The invention relates among others to a lamp (10) for mounting on a building surface or a part of a building, like for example on a roof or a ceiling, a wall or a floor of a room, comprising a support device (12) or a plurality of light emitting diodes (29) and a light fitting element (21) which has a light entry area (28) adjoining the support device (12) for light which is supplied by the light emitting diodes (29), a light output area (30) and a light guide segment (27) which connects the light entry area (28) and the light output area (30) with one another. The particular subject matter of interest resides in that the light guide segment (27) has curved internal surfaces (30) and that the light is passed from the light entry area (28) to the light output area (30) through the light guide segment (27) basically with a multiplicity of reflections on the internal surfaces (20).