New Williamsberg is a 3v3 map created for the 2016 season 1 ladder of Legacy of the Void. It was removed in the 2016 season 3 map pool.
Official Map Description
The air to air distance to the enemy's base is extremely close on this map. Watch out for early attacks from flying units.
References
Blizzard Entertainment. StarCraft II. (Activision Blizzard) Map: New Williamsberg (in English). 2016.