Nancy Holt (1938–2014) was married to the land-art legend Robert Smithson. She began her practice in photography and video, and in 1974 collaborated with Richard Serra on a radical audio project called Boomerang. Holt eventually began making land art, works she described as “seeing devices, fixed points for tracking the positions of the sun, earth and stars.” Room-sized installations fill the galleries in this exhibition; there are also projections and drawings. Holt’s oeuvre, focused on issues of time and space, once seemed esoteric. Now her art feels eerily contemporary. And her own legend grows. —Elena Clavarino