I really like hiking. Currently, I live in Mainz, which has nice countryside nearby to walk in, especially downstream along the Rhine. Since I have only just moved here, a lot remains to be explored. The hilly surroundings of Mainz are a definite upgrade to the Dutch countryside, where hills and mountains are (famously) sorely lacking.
Our holidays are usually centered around going hiking up a bunch of hills or mountains somewhere (because back in The Netherlands, this was impossible). We mainly stay in Europe; Scotland, Austria, and Switzerland are personal favourites, although we are still young, so more destinations will undoubtedly follow.
Sort of related to that, we love to travel by train. Trains feel much more adventurous then planes, even if they aren’t really (unless you are in Germany - thanks DB). And of course trains are better for the environment.