If you’re even remotely geeky about trains and railway networks, this is worth a look. It’s a “geographical” map of the London tube network, it includes all current lines and stations, but also all historical lines, stations, part-built stations, etc., and it shows sidings and train yards, etc.  It’s geographically accurate, it shows where the lines actually run, including where they cross each other (e.g. the diving pass the Victoria line makes just south of Warren Street), the turning loop at Kennington, the way the platforms are staggered at Picadilly…

Just as much a work of art as the “traditional” tube map is often regarded.