Sutherland, South Africa
The South African Astronomical Observatory is home to the South African Large Telescope—or SALT—the largest optical telescope in the southern hemisphere. It's so powerful that it can detect objects that are a billion times too faint to be seen with the naked eye. Visitors can tour the observatory by day, or head back after sundown, when they can get a look at the night sky through two dedicated visitor telescopes. Unfortunately, though, visitors can't have access to the research telescopes at night—the lights from their cars would block the view.
Visit: Full, guided tours through select research telescopes and the SALT take place Monday to Saturday from 10:30 am until 2:30 pm. Shorter, more basic tours of the SALT take place Saturdays, every hour on the hour, between 8 am and 3 pm. Night tours, which last 90 minutes, take place every Monday, Wednesday, Friday, and Saturday. Advance reservations are required for all tours.
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