This node is seriously in the wrong place. Was the restaurant really on the corner of Washington and Washington Court in May of 2018?

I have moved it to the actual location based on on-the-ground survey.

What "city map"? What is the copyright status/license of it? How can I look at it?

According to the MassDOT data set as shown in MassMapper, Meadow Pond is a public road, with a 35' right of way. It may be that the marking is improper, which would not change access. I'll see about contacting Concord, after finishing up with Acton :-)

L3 parcels shows Anthem Way and the other 3 as a public right of way. I intend to inquire of the town; it seems that either L3 parcels is wrong or the signs are improper.