For a slightly different tourist jaunt through the S.F. Bay Area, how about visiting the cold war missile sites? If you think that won’t take too long, well, there are at least 24 sites related to the Nike missiles. As Jef Poskanzer describes on his comprehensive website: “Each Nike installation was split into a radar/control site, high on a hilltop for good visibility, and a launch site somewhere lower down and a mile or two away for better protection.” Tom Stienstra at the Chronicle has picked his top five Nike sites, all the better for educational hike planning.