At the turn of the 20th century, Alum Rock Park had 27 mineral springs, an indoor swimming pool, tea gardens and a restaurant. Visitors arrived by a steam-driven railroad. Today, all of that is long gone. But you can still walk to the stone grottos that housed the springs and see remnants of the bridges from the train line. Visiting Alum Rock is like visiting an outdoor museum. There are signs and plaques and old stone pilings that tell this history. The park is celebrating its 150th anniversary this year, with events scheduled through October, including many guided walks.