Geezers here who think they’ve seen everything are unlikely to have checked out two unique islands right in front of our noses. Just off Richmond with a little effort you’ll find Brooks and Brothers Islands.
Brooks is 373 emerald acres, a baby Galapagos, home to 18 bird species including herons and egrets. Part of the East Bay Regional Parks it is accessible by reservation. The price for non-residents of Alameda County is $22. On the other hand if you have access to a kayak you can DIY. Find a detailed account from a naturalist point-of-view here.
Brothers Island is even smaller, a mere chunk of rock also off Richmond. A lighthouse built in 1877 it is now a charming kind of twee b&b with knockout views of the city. There are only five rooms each more cozy and Nor’eastern than the next. You get a champagne welcome, a major dinner and breakfast starting at $295. If you stay two nights you’re allowed to use the shower.