Attention, city dwellers! We're interested in identifying university-owned or commercially managed underground urban tunnels & facilities able to host research & experimentation. https://t.co/tHZ1Tqy5nV

It's short notice... We're asking for responses by Aug. 30 at 5:00 PM ET. pic.twitter.com/TSWO07bJam

— DARPA (@DARPA) August 28, 2019