Frank Lloyd Wright's "beautifully maintained" winter retreat and studio is an "architectural wonder" made of rock and wood that "captures Southwest colors and textures" while providing "instructive insight" into the "work and life" of "America's premier architect"; "nirvana if you're into" buildings and a "must-see" even if you "don't know much" about them, this "hidden" Scottsdale "gem" offers a "variety of tours" that are "pricey" but "worth" it.