Patent ID: 8091315

Claim:
A building block made of a cast material, comprising: a first outer lateral surface, an opposite second outer lateral surface, a length extending between said first and second outer lateral surfaces, and light transmitting fibres, including optical fibres, embedded in the cast material, each of said light transmitting fibres having a first end and a second end. each capable of receiving impinging light from a light source and guiding the light toward an opposite said end, said fibres being arranged in the cast material so that said first ends of said fibres terminate at said first outer lateral surface of the building block and said second ends of said fibres terminate at the opposite second outer lateral surface of the building block, said fibres defining a plurality of generally parallel longitudinal layers extending along said length of the building block, wherein said fibres permit transfer of light through the building block emitted from,a light source arranged behind one of said first and second outer lateral surfaces so that light can be emitted evenly distributed over substantially said opposite outer lateral surface.