The Ladd Observatory on Hope Street was built in 1891 for Brown University's astronomy program and has been open to the public for stargazing on Tuesday evenings since its construction — making it one of the longest-running public observatory programs in the United States. The 12-inch Alvan Clark refractor telescope dates to 1891 and is still in use.
The building sits on a small hill in a quiet residential neighborhood north of Brown's campus. Public nights run year-round, weather permitting, and admission is free. The observatory also hosts occasional lectures and educational events. A visit here is a good example of Providence's habit of maintaining institutions that other cities would have converted or closed long ago.