Michael Heizer's City.

 In 1972, Michael Heizer began construction on the massive installation known as City in the desert of Lincoln County, Nevada. 

Thanks to Scott Dorrance for the heads-up on Michael Kimmelman's piece on Michael Heizer in the NYT last month: " “City” ... may be the most ambitious sculpture anyone has ever built, one of those audacious, improbable American dreams, at the scale of the West, conceived for the ages. More than a mile long, “City” is a kind of modern Chichen Itza in the midst of Garden Valley, a pristine, lunar stretch of stark and unspeakable beauty, an hour’s bumpy drive from the nearest paved road..."

There's a show--his first in years--up for a few more days at Gagosian in NYC: 18-ton slab of granite named "Potato Chip" and a 12-ton rock of iron ore called “Asteroid.”