An anime trying to make mountaineering popular
When I first watched Yama no Susume, it was quite obvious that the anime was also trying to get young people to go visit the mountains... and what can I say, it worked. If it wasn't for Yama no Susume, I wouldn't have had any interest in Mt. Fuji. But it's not just Fuji on these girls' minds, as they venture up many a mountain for fun.
If the first season wasn't a bunch of short episodes, I probably wouldn't have picked it up; I was watching short series' on my lunch break at the time, and Yama no Susume was one of the few short anime that looked remotely interesting.
The second season switched to a more "normal" 24 minute episode length, which I was sceptical of, but it worked out very well. The third season focus a lot more on Aoi and Hinata's relationship, whilst also continuing to teach a little bit about mountaineering along the way.