In a valley in the Diablo Range foothills sits Alum Rock Park. Its name derives from the fact it was once thought the nearby rock formations contained aluminium. In fact they don't, but the name stuck. Alum Rock Park consists of 290 hectares of idyllic forest, hiking paths, and creeks.

Begin at the visitor centre, where you can peruse maps and find the right walk for you. Hikes around Alum Rock Park vary in difficulty, and there is at least one to suit all types of walker. For excellent vistas of the Bay Area, opt for the North Rim Trail to Eagle Rock. Otherwise, take things easier with the Penitencia Creek Trail, which transects the entire park and provides ample vantage points and picnic areas along the way. Other highlights around Alum Rock Park include various active mineral springs and grottos, stone bridges, a gazebo, and a log cabin constructed in 1913.

The flora of Alum Rock Park is diverse; on the south-facing slope you'll find the likes of poison oaks, sage brushes and various wild grasses. On the north-facing slopes, big leaf maples, ferns and oaks flourish. A plethora of wildlife inhabits the land around Alum Rock Park. Be prepared to run into turkey vultures, wild turkeys, bobcats, black-tailed deer and California quail. The occasion puma has been spotted roaming the area too.

If you're a family with young children, make the most of Alum Rock Park's playground, and the Youth Science Institute, an educational experience that delves into the area's natural history.

Alum Rock Park is a 20-minute drive from San Jose, open from Tuesday to Sunday. Buses are laid on from downtown San Jose, but the stop is around 20 minutes' walk from the park itself. Getting a parking space can be competitive, especially at weekends. Come early on a weekday if possible. There is a charge for parking.