Answer: arecibo

AnswerCrossword Clue
ARECIBOPuerto Rican seaport
ARECIBOPuerto Rican city
ARECIBOPuerto Rican seaport.
ARECIBO... Observatory, home of the world's largest single-aperture radio telescope
ARECIBOPuerto Rico's -- Observatory
ARECIBOPuerto Rican port
ARECIBOPuerto Rican observatory named for a nearby port
ARECIBOPuerto Rican home to the Western Hemisphere's largest radio telescope