I remember watching this cartoon as a child. In the first episode these three kids went camping with their parents. The parents slept in one tent and the kids in another. But when the kids wake up the next morning and exit the tent they find that they are in a different world/dimension with all these alien plants and monsters. I think they went to a different world every day to try and get back to their parents. All three kids were siblings. They were different ages but I don't think any of them could have been older than 14-15. I think the youngest was still little. at least one of the kids was a girl. Some of the monsters helped them, but others were dangerous. I don't think there was a reoccurring villain in the show.
The show aired where I live(Estonia) in the middle of the '00s or so(2005-2010 I think), but we often get shows a few years after their release and this was definitely a foreign show so it could have been made in the 90s too.
This has been driving me up the wall for a few years now and I just can't find it. At this point I would be happy just to find someone else who has seen it and can confirm I'm not crazy!