The Chabot Space & Science Center is another observatory that is not as far outside of a city as you might expect. Located in the Oakland hills, it is just a 25 minute drive outside of San Francisco. The observatory features three impressively large historic telescopes that can offer an insight into both the cosmos and the study of them. There is a General Admission option during the day, but every Friday and Saturday night between 7:30 pm and 10:30 pm, stargazers are welcomed free of charge for some incredible night time viewing.