We revisit swimmers’ paradises from Malibu to Tangier. Great Spaces We revisit swimmers’ paradises from Malibu to Tangier. Great Spaces The pool at the actor Robert Downey Jr.’s home in Malibu, Calif.

We’d never had a pool before, but the house came with one, which was part of its appeal, at least in my eyes. We were in our early thirties then, with two children—Molly, four, and Jordan, two—and we ...