Norngarden 4 (aka Aqua-garden) is the fourth of four (Norngarden 1, Norngarden Xmas, Norngarden 2) metarooms designed to fit together. It was created by Tomtschek.
"The Norngarden is a biosphere module that can be connected with the Docking Station and the Shee ship. Its not totally clear if its origin was Shee or not. It is not known if all these plants are artificially created or collected." -- Taken from the Norngarden homepage.
Norngarden 4 is the home of the Aquanorn, and is only available through the Give-to-Get-Special. Norngarden 4 overlaps with the Monturarrium.
Note that the room is missing a soundfile, so eating the critters will cause an error when the game can't find it. (This can be gotten around by copying one of the food-eating sounds that comes with the game, then renaming it 'mapf.wav'.) The critters are edible, but they give inconsistent stims for eating them and not the one for eating animals. It is also possible for creatures to fall off the upper level areas and into the pond.