[schroeding]

Not GP, but you have e.g. Brocken and Cologne as targets, but the former is (the summit of) a mountain, the latter a city. A categorization of the destinations (maybe based on wiki voyage metadata?) may be a good addition for your very nice web app.

BTW: You have Heligoland[1] as a reachable destination. I don't think that's actually true, those are real high sea ferries for which, AFAIK, the 49 Euro ticket is not valid. :)

[1] https://en.wikivoyage.org/?curid=14437

[whinvik]

Yeah, that would be a cool idea. Will put it on my ToDo list.

Nice catch on Heligoland. Thanks. The final journey is via Schiff and I had not filtered that out. However, I don't know if DB categorizes Schiff that are included or excluded from the 49 Euro ticket.