Professor Oak's Lab
Once just a simple house with a barn-sized, two story lab attached to it, Professor Oak's Lab has, over the years, been expanded by the Pokemon league into a veritable fortress. Still sitting on a hill overlooking most of Pallet City, Oak's lab is a walled compound approximately as big as two foot-ball fields placed side by side. The walls are twenty feet high and thick enough for three men to walk abreast.
There is a Security checkpoint just inside the compound's only gate, which is always manned by at least 1 of the trainers that provide security for the lab.
In addition to providing storage for the League's starter Pokemon, and spectacular and rare specimens captured by league trainers for study, the compound provides a barracks area for any of the researchers and security who wish to remain onsite. Professor Oak's private residence is still a part of the compound as well.