Not sure about closures, but I suggest you see the following in California:
Yosemite National Park
If you can park at Yosemite creek campground and hike the 5 miles to the rim of the canyon. You will see square miles of glacier carved granite.
Hearst Castle
Unlimited money built something amazing.
Walk across the Golden Gate Bridge.
Good, clear weather. Your 300 feet above the water and the bay would be full of sailboats. Beautiful and lots of fresh air. Don’t wear shorts or short sleeves.