The hook
On a peak above the city sits the telescope where a man looked out one night in the 1920s and found that the universe is far larger, and stranger, than anyone had believed.
01Why it's worth it
When the hundred-inch telescope opened on Mount Wilson in 1917 it was the largest on Earth, and it stayed that way for thirty years. It's the instrument Edwin Hubble used, up here above the lights of Los Angeles, to prove two things that broke the sky open: that the faint smudges called nebulae are in fact other galaxies, millions of light-years off, so the universe is vastly bigger than our own Milky Way; and that those galaxies are all rushing apart, so the universe is expanding. Modern cosmology essentially begins in this dome. You can visit the historic telescopes, walk the piney ridge, take in the same basin view the astronomers had, and on some nights the public can actually look through the hundred-inch itself.
02How to experience it
It's at the top of the San Gabriels above Pasadena, about six hours from the Bay, up a long mountain road that's open seasonally and weather permitting. Grounds and tours run mostly on warmer-month weekends, so check the schedule, and look into the public viewing nights if you want to see through the big telescope. It's cool at altitude, so bring a layer.