First portal
Marquis said that you can find the first portal from the tree you used to get to Mousewood initially. Head to the forest crossroads from the front gate and onwards into the woods.
Guide listing help
Unlike normal walkthroughs, in Nice Game Hints you can select just the puzzle you want hints for. Here are listed the puzzles for "First portal" in Night of the Rabbit. The guide you choose only contains information about that puzzle, reducing possible spoilers for other puzzles.
Hints written by Juho Rutila
Juho Rutila
I believe adventure games should be more accessible for all gamers. That's why I wrote these hints.