I don't know if they meet your "architectural significance" criteria, but:
1. Richter Park, Danbury CT. - penal, but aesthetically diverse design from the same architect who created Morefar (a sliver of which is visible across Boggs Pond from Richter's 12th green)...once a GD Top 25 public. Water hazards in direct play on 13 of 18 holes.
2. Longshore - Westport CT. - very sporty, "antique-feeling" Orrin Smith design that has markedly inproved conditions from decades past..often called a hidden gem.