Los Angeles County Museum of Art

Stand on Wilshire Boulevard after dark and the first thing you see is not a building but a grove of 202 antique street lamps, packed tight and all switched on. Chris Burden gathered the cast-iron lamps from across Los Angeles, restored them, and set them up in 2008 as Urban Light, which quietly became the most photographed spot in the city.

Behind it spreads the largest art museum in the western United States, nearly 140,000 objects covering some 6,000 years, from ancient Egypt to Hollywood-era design. Out at the eastern edge lies Levitated Mass, a 340-ton granite boulder that Michael Heizer had hauled 105 miles across Southern California in 2012 to sit over a walkway you pass beneath.

The heart of the campus is being rebuilt. The Swiss architect Peter Zumthor has replaced four of the old buildings with a single low, dark concrete gallery that bridges Wilshire Boulevard, so the collection will soon hang in rooms that float over the traffic below.