Photos: The stunning Sun Tunnels

Of all the 5,600-plus miles I drove during Road Trip 2009, none may have been more focused than the 320 or so I drove on the Fourth of July to see artist Nancy Holt's terrific Earthwork, the Sun Tunnels.

Built between 1973 and 1976 on 40 acres of Great Salt Lake Desert land near the tiny town of Lucin, Utah, "Sun Tunnels marks the yearly extreme positions of the sun on the horizon," wrote Holt in 1977, "the tunnels being aligned with the angles of the rising and the setting of the sun on the days of the solstices, around June 21st and December 21st. On those days, the sun is centered through the tunnels and is nearly centered for about 10 days before and after the solstices."

Click here for the entire Road Trip 2009 package.