“Step Into the Void” by Pierre-Yves Chays (2013)
I am not sure if this is an example of urban intervention, but I found the piece incredibly interesting and wanted to share it since it is a large-scale work that responds and alters an environment. This installation is built on one of the highest portions of Europe’s tallest mountain in the French alps. Visitors can step out into the glass cube to interact with and view the mountain range in a way that is completely foreign to man. (It also makes my knees wobbly just thinking about it.)
More information here.