A beautiful old map showing Hamburg’s Ringbahn and spur lines. I believe that this map is from no later than January 1912, and it may be from even earlier, as the legend denotes that all the routes shown in red (the beginnings of today’s U-Bahn system) are “intended for execution” – that is, planned or under construction, not actually built.

Construction of the Ringbahn began in 1906, and the first section between Rathaus and Barmbek stations was opened on February 15, 1912. The ring was completed by the end of June that year. The spur lines as shown on this map opened in stages between 1913 and 1915.

See also: this amazing Hamburg train carriage ceiling map from 1915.

Source: mapsolutely/Tumblr