I looked through the threads and thought it remarkable that three sites I was familiar with are not yet listed.
1. Harvard Square, Boston, the coffee shop (or cafe, formerly Au Bon Pain, may be a Starbucks now). This is a huge one, usually at least 20 players in the al fresco area plus maybe 3 tables going inside. There are 6-8 stone tables with the 64 squares etched in (people often just put a vinyl tourney board over it. Usually going until the cafe closes, around 2 am. Occasionally I found bridge players here, too (no one in my age groups know how to play bridge! They are usually my grandmother's age!). Variable strengths from Master on down. People will play at all hours into the night/morning. Rain or shine, you'll always find a game going. Most anyone you ask in Boston about this will know about Harvard Square's chess 'park', even if they don't play chess. BTW, there is an excellent 7 day/wk chess club in Boston, the Boylston Chess Club.
2. JFK square, downtown Philadelphia (aka Center City), just north of the City Hall on Market St. At least there was one during the mid-1980s. People would play on the benches & steps of the fountain there. Usually going during the day; inadequate lighting & safety issues (Philly cops are not to be messed with. Period.) This one has hustlers, so beware. At the time, the funny thing was that often times I was the only white guy there (the funny anecdote is when I was playing one of the stronger players, money was changing hands behind me, and one said "I'm betting on the white guy!")
3. The KFC on Canal Street, Vieux Carre (Bourbon St. area, old New Orleans). Not so much a park but on the sidewalk under the canopy--usually about 2-3 games going on those fold-up conference tables that can fit two boards. Definitely hustlers there! If you beat them (when I was last there, I'd put them around 1600-1700 strength), some will throw their money down on the board in disgust and not play you anymore. I haven't been down there since 1998, but the three times I was there for conferences at the Riverwalk there was something going.
I live in North Carolina--I know of several chess clubs, but no outdoor venues I'm aware of.
Someone may be able to verify the last two venues. The Harvard Square site is an institution.
-d nemo
P.S. I'm looking for parts or repair for my BHB Turnier analog clock. Does anyone know of anything like this?