Oldest purpose built transmitting tower

A steel television transmitting mast was erected between 1935-1936 on top of the south-east tower of Alexandra Palace (built 1871), London, to the designs and specifications of John Logie Baird, the BBC and EMI-Marconi. It transmitted the world's first high-definition (405-line) television service from November 1936. The antenna wires and wooden stretchers were removed in 1956 when Crystal Palace took over television broadcasts for the south-east, but the mast continued to be used for experimental broadcasts, including the first colour transmissions in the UK. It is still used as a booster transmitter for the BBC and ITV television signals in north London and digital radio for the BBC.