Independent specialized forums

Hello everyone

, recently I discovered iNaturalist, an app to make record observations of plants & animals in nature and try and identify them, even though I've been using it for 2 weeks only I am REALLY enjoying it. it never serves any ads and its community is really nice and supportive/welcoming.

iNaturalist has a sister forum at forum.inaturalist.org and its one of the highlights of this community, a lot of the app's top experts hang out there but there are also lots of normies (like me) so questions on the forum aren't immediately disregarded as too simplistic. I asked a question and got 40+ constructive replies within 2 days, way more than I would have got on certain subreddits. and the best part is that it is independently hosted! (just like MelonLand Forum)

so I began a hunt for other independent forums that focus on specific niches like iNaturalist, where knowledgeable people hang out. at the moment I am in my nature arc so I got really into these subjects and I am looking for forums for them:
- Stargazing, the solar system.
- Natural navigation: using natural signals (wind, trees, water, stars, etc.) to guess cardinal directions and more
- Geology
- the study of fossils.

But if you know another independent forum that fits this vibe please share it even if its outside these interests. I want everyone to benefit from this and maybe I'll discover another interesting hobby through your suggestion.