A Banshee
In the south coast, the storage type secret plane Leylin had previously raided and the laboratory type secret plane that the old witch found were all classified as small scale secret planes.
The area of these kind of secret planes usually didn’t exceed a 100 mu and were only used to perform experiments and to store supplies. If one does not take into account of the items stored inside and only look at the area of the secret plane, its worth would be at the bottom.
Above that were the resource type secret planes, the area of that type of secret planes is usually larger than 100,000 mu. The area is large and the topology is varied and suitable to grow resources necessary to Magi.
The highest rank of secret planes are those that have spells that can adjust the living environments of both plants and animals, and can be controlled by a single Magus!