Earlier this year the blog Conoperative put up a photo tour of what remains of Dupont Down Under, the trolley subway turned failed retail venture beneath Dupont Circle. One highlight is below; for the whole tour, go to Conoperative.

The trolley subway, with closed shops in the shape of trains on the left.

Update: Coincidentally, DC economic development officials said yesterday they are preparing an RFP for development of the tunnels. – 12/11/09