If you have more time to spare, you can explore more of nature at nearby Mount Diablo State Park, or visit the Markham Nature Park and Arboretum for a smaller, relaxing stroll. If you're in town for a longer period, consider exploring other Bay Area cities like Oakland or San Francisco by taking BART (Bay Area Rapid Transit) from Concord's station. Also, if you're in a hurry, subtract Galindo House and Gardens as it is the costliest place and add a visit to the Benicia Arsenal.