The Monte Ceneri transmitter was first established as the nationwide medium-wave radio transmission station for Italian-speaking Switzerland in 1933. Located on Monte Ceneri in Ticino, it broadcast on a frequency of 558 kHz.
Wikipedia https://en.wikipedia.org/wiki/Monte_Ceneri_transmitter
Address (Unnamed Road), Monte Ceneri 6802, Switzerland
Coordinates 46°8'26.211" N 8°54'56.325" E
