Puerto Rico Highway 21 (PR-21) is the main highway to get to the Medical Center and Veterans Hospital in San Juan, Puerto Rico. It begins in PR-19 in Guaynabo to San Juan before ending in PR-1. History PR-6 was previously numbered as PR-21. Perhaps there were plans to connect current PR-21 to current PR-6, but such plans were never realized. Major intersections See also List of highways numbered 21 References External links 021 Roads in San Juan, Puerto Rico