On August 28, DARPA tweeted and FedBizOpps a request for unused underground
What they want
The requirements for such rooms are quite specific: the whole complex should occupy several city blocks, have a complex structure, several levels and various variations of atriums and stairwells.
One cannot fail to note the urgency of DARPA's needs: the owners of the premises can send them their proposals until August 30.
What is it for them?
The purposes for which DARPA is looking for premises, of course,not disclosed. However, most likely they are much more prosaic than the opening of aliens or experiments to create a super-soldier. Such isolation is a great help in the study of radio waves, when the outside world minimally affects the object of research.