Run by the National Science Foundation, the observatory has a public outreach center where you can learn more about how the telescope works and how it’s being used in modern scientific research. Exhibits cover topics such as radio astronomy, the solar system, and Earth’s atmosphere.
An auditorium screens a 20-minute film throughout the day, while an observation deck looks out over the immense reflecting surface of the telescope itself. Day trips to the observatory often include a visit to the nearby Window Cave (Cueva Ventana) or Cueva del Indio, both home to prehistoric rock art.
The observatory is located along Route 625, about 60 miles (100 kilometers) west of San Juan. The drive can be a bit challenging for those not used to island driving so opt for a tour in order to skip the hassle of car hire.
The visitor center is open from Wednesday to Sunday each week, and closes mid-afternoon. Plan to visit on a day with no rain forecast to make the most of your time outside on the observation deck.
Among the many projects carried out at the observatory is an ongoing search for intelligent extraterrestrial life. In 1974, Frank Drake and Carl Sagan transmitted what is known as the Arecibo message to the M13 star cluster 25,000 light years away. The binary message, when decoded, contains pixel bitmaps showing a human, the solar system, the telescope itself, and several chemical formulas.
