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Mount Umunhum, San Jose

4.7
#10 of 26 in Parks in San Jose
Mount Umunhum is the fourth-highest peak in California's Santa Cruz Mountains . The mountain is situated in Santa Clara County, south of San Jose. It is sometimes referred to as Mount Um by locals. Most of the mountain is within the Sierra Azul Open Space Preserve.
The mountain is topped by a five-story concrete radar tower, known locally as "the Cube" or "the Box". The tower was part of Almaden Air Force Station, a radar surveillance post which operated from 1958 to 1980. The Cube, which housed an 85.5-ton AN/FPS-24 radar, was completed in 1962 and used to watch for hostile aircraft during the Cold War.
The summit was closed to the public due to hazardous materials and unsafe, partially demolished structures from the former Air Force station. Plans are underway to clean it up and restore it for public use. "In 2009, with federal funding, Midpeninsula Regional Open Space District removed 3,000 cubic yards of hazardous materials, including lead paint, asbestos, fuel storage containers and PCB transformers; and deconstructed 13,680 tons of concrete, asphalt, wood and other materials." The demolition of the cube was considered, but in May 2016, the Santa Clara County Board of Supervisors listed it on the County Heritage Resource Inventory, giving it official historic status and protecting it from demolition. In summer 2017, a mountain biking and hiking trail to the summit will be opened, once facilities at the summit have been completed. It will be a spur of the Bay Area Ridge Trail. It is planned to open to the public on Monday, September 18, 2017.
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Mount Umunhum Reviews
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TripAdvisor Traveler Rating 4.5
27 reviews
Google
4.8
TripAdvisor
  • There are hiking/mountain biking trails starting about half way to the summit. However, parking is extremely limited. You may have to drive to the top to park then ride or hike down from there. The vi...  more »
  • The view from here was another attraction, unlike other landscapes that look from different angles. I like this very much.
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Google
  • You can see Santa Cruz and San Jose from up here. At night it is the most beautiful spot in the entire valley. It is also good for a down hill day hike.
  • Great view of Silicon Valley. The parking and new facilities are great. Road can be challenging unless weather is good.

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