The optical telegraph in Grisslehamn

In 1796 an optical telegraph was built on Utkiksberget (south of the bathing bay by Albert Engström's Studio). It was used to give early warning of the attack by a hundred Russian Cossacks led by Cossack colonel Kullnef in 1809.

With the help of the telegraph, much of the contact with Finland was handled via a corresponding station on Signilskär in Åland, right up to the latter half of the 1800s. Each station was a link in the chain where the signals were repeated step by step until the message reached the final station. It took less than half an hour to send a message from Grisslehamn to Stockholm. A mounted orderly needed two or three days. In 1994, on the 200th anniversary of Edelcrantz's invention, the Telemuseum had a replica of the telegraph built on Gärdet in Stockholm. When the Telemuseum closed in 2004, the collections went to the Museum of Technology, which donated the telegraph to Grisslehamn and Norrtälje municipality. In 2014 the telegraph was erected on a rocky knoll on the grounds of the Albert Engström Museum, close to its old location on Utkiksberget.