Puerto Rico Highway 303 (PR-303) is a rural road stretching between the municipalities of Cabo Rojo and Lajas in Puerto Rico. It begins in PR-301, in southeastern Boquerón, Cabo Rojo, passing south of the Sierra Bermeja before leading northeast, where it passes PR-305 and ending at a junction with PR-101. The stretch of the road spanning the southern border of Sierra Bermeja is popularly known as the Puerto Rico Alien Route (Spanish: Ruta Extraterrestre) due to the number of UFO reports associated with the area it crosses.
