From the competition brief:

"Exterior

The site is seen as essential part and "first exhibit" of the documentation "Topographie of Terror" by the foundation. In its bare inhospitality it aspires to trigger mediation and be perceived as "disturbance of the usual".

The historic site achieves particular relevance through the excavation of building leftovers. It shall be made perceivable further on and shall be generally more perceptible than it has been. Material traces as well as historic layering and designs that were not realized shall be made historically accessible by an information system.
The existing material traces shall be conserved for the long term; they shall be secured and eventually cautiously restored. The technical expense will vary with the historic relevance of each part. Those two objects preserved by historic conservation - the base memorial [former basement prison cells] and the Berlin Wall- will require eminent securing.

An artistic overall design for the site or even the reconstruction of the park designed by Peter J. Lenne is not desired. Everything "flashy" shall be avoided; the "prosaic" character of the site shall be retained. In the east of the site, south of the excavation, an open area shall remain - as it did before with meager steppe-like vegetation.
[...]

Main entrance from Nieder Kirchner Strasse (side Martin Gropius building), but observe the exisiting entrance from Wilhelmstrasse. Possible other entrances are south of the Martin Gropius building. A delivery emtrance shall be provided.
Internal acces shall be achieved as a tour
[...]
Walkways shall be permeable for water and to be used all year long and, like the now existing resin bound surfaces, easy to maintain.
The site shall be enclosed, its open character shall be maintained."

More Thursday...!