Shortly after the telephone was patented in the late 19th century, the early technology required every phone to have its own dedicated connection to the grid. In Sweden, Stockholm’s main telephone exchange – the Telefontornet, built in 1890, was a huge tower in the centre of the city with 5,000 individual lines radiating out across the rooftops.
The typically harsh Swedish winters caused havoc with the system, which was prone to fire and collapse under the weight of hanging ice, but the rapid advance of technology allowed the tower to be decommissioned in 1913. 40 years later, it caught fire and was demolished.
Hundreds more images at the Tekniska Museet (Museum of Technology) website.