Arecibo C3 STEM Center

Arecibo C3 STEM Center is the public-facing education and engagement destination at the federally owned NSF Arecibo Observatory Historic District, preserving and interpreting the landmark observatory radio-astronomy legacy after the former 305-metre telescope ceased operation. The Science and Visitor Center presents the Signals exhibition, historical interpretation, views of preserved telescope remnants, hands-on STEM activities, workshops, talks and field-trip programmes. Public access is partial and calendar-controlled while facilities and programmes continue to develop. The operator’s current ticket guidance says there are no general-public tours on Fridays or Saturdays in August 2026; these are expected to resume in September, with ticket sales planned for late August. All visitors must reserve online at least 24 hours before an event; tickets are not issued on-site unless a same-day online allocation has already been reserved. This historic site has uneven or restricted areas and a steep approach of about 500 steps, so accessibility varies; cell phones, Bluetooth, drones and other radio-interfering devices must be disabled on site. Check the operator for current hours, tickets and reservations.