Bunthäuser Spitze Lighthouse is easy to reach by bicycle, no necessary rent a car,
https://goo.gl/maps/qag5MWQqMGR2
Blankenese Low Lighthouse,
Leuchtturm Unterfeuer Blankenese is easy to reach by bicycle, no necessary rent a car,
https://goo.gl/maps/oQkkLoC5BFG2
Ellerholzhafen lighthouse is so easy to reach by bicycle, no necessary rent a car,
https://goo.gl/maps/G99Ei3J9QVE2
Wittenbergen Unterfeuer is easy to reach by bicycle, no necessary rent a car,
https://goo.gl/maps/d2RkPPEtNvQ2
Juelssand lighthouse, is 35km away,
https://goo.gl/maps/JLGsJ83mLVv
Bergwind, You missed it !
You are right, I missed Juelsand lighthouse, also some other lighthouses in Hamburg, see my to do list! :)
Juelsand seems to have no land access, but I have noticed for a picture from other side of river!
Maybe next year.
Now I preparing a trip to Teneriffa!