Sioux Falls was built on quartzite. In the 19th century, when the first settlers arrived they found that wood was scarce. After Sioux Falls became established, local entrepreneurs realized the pink quartzite that rose in great ripples and low plateaus in the area could be quarried and used for street pavers, buildings and other things.

I don't know where this particular pile of quartzite blocks came from. The pile sits on the west side of Falls Park amidst grass, trees and more unquarried quartzite rising out of the ground. I thought it might be fun to model it just to see how much detail I could capture.