I think that this photo, shot from above, gives one a sense of the scale of size of the slurry wall, which survived the 9/11 attack on the World Trade Center. This below-ground, concrete structure, surrounding the World Trade Center, was designed to keep its basement levels from being flooded by the Hudson River.  It is preserved as a part of the 9/11 Memorial.

My submission to The Daily Post Weekly Photo Challenge Scale

Slurry Wall