If you’re heading around the Great Loop, or simply cruising up and down the Intracoastal Waterway, you may want to schedule a stop at the facedock at the Dismal Swamp Canal Welcome Center in North Carolina, just south of the Virginia border. It’s always been a friendly spot to rest or spend the night; indeed, about 2,000 boats stop there each year. But now it has some added cachet: Architectural Digest just named it one of the 15 most beautiful rest spots in the U.S. The state-run welcome center serves as a gateway to the Dismal Swamp State Park just across…