The hook
A Santa Cruz Mountains summit crowned by a five-story concrete Cold War radar cube, closed to the public for 60 years and only reopened in 2017.
01Why it's worth it
From 1958 to 1980 this was Almaden Air Force Station, scanning the Pacific for Soviet bombers; the giant radar tower — "the Cube" — is visible from most of the South Bay, and for decades that was as close as anyone got. Now you can drive nearly to the 3,486-foot summit and walk the last ten minutes to a 360° view that runs from Monterey Bay across the whole Santa Clara Valley to the far side of the Bay. The mountain is also a sacred Ohlone site — the summit restoration includes a ceremonial circle — which gives the place an unusual double weight: missile-age paranoia and something much older, sharing one peak. Locals pitch it simply: half-hour drive from the Camden exit, easy walk, "with a view like that, I'll make out with anything standing next to me."
02How to experience it
Take Hicks Road out of San Jose — narrow, steep, and beautiful — then Mt Umunhum Road to the summit lot. Free. Read the interpretive panels; the Cube itself is fenced but imposing up close. Cyclists treat the road as one of the South Bay's serious climbs. Combine with quicksilver-mining history at Almaden Quicksilver park below.