The Einhel Keep (アインヘル小要塞) is a unique, indoor training facility for the Thors Branch Campus designed and built under the supervision of Professor Gerhard Schmidt.
The Einhel Keep was built as Professor Schmidt's requirement to stay affiliated with the Branch Campus. Enormous mechanisms allow changing the interior of the facility at will, making it a perfect place for students to practice their combat or give new weapons a try. With a terminal serving as a control panel, it is possible to adjust the difficulty level according to the trainee's growth. It is specifically built on top of a septium vein to allow its interior to have control over the higher elements.
The new Class VII starts the school year by being dropped into the Keep's basement, like their predecessors in the Old Schoolhouse. Professor Schmidt regularly demands that they pass his new designed levels, with Tita Russell at his side as his apprentice.