Share to Facebook Share to Twitter Share to Linkedin The St. Pauli Bunker, also known as the Green Bunker or Grüner Bunker, with the new Reverb hotel and ..

. [+] roof garden. Christopher Elliott A World War II bunker turned into a hotel.

A food hall filled with locally grown vegetables. And vast stretches of ambitious green spaces that tourists are helping keep clean. Those may not be the first things you think of when you come to a place like Hamburg — a German port city known for its vast network of canals and tasty Fischbrötchen , or fish sandwiches.

But this summer, just as the European soccer championship was wrapping up, two new sustainability-minded attractions opened in Hamburg. They complement the city's already worldwide reputation for parks and green spaces, which the government is now giving a nudge with an unexpected tourism angle. (Hamburg already has far-reaching sustainability goals outlined in its Agenda 2030 plan.

) Put together, these developments speak volumes about Germany's commitment to sustainability in tourism. They're diverse and creative, perhaps even a little unorthodox. And they're off to a promising start.

A view of the roof garden at the top of the bunker with Hamburg's iconic Heinrich-Hertz-Turm, a ...

[+] television tower, behind it. The roof garden is accessible to the public. Christopher Elliott A new hotel in the Grüner Bunker One of Hamburg's newest sustainable attractions, opened just last month, is the Reverb by Hard Rock Hotel , .