Isometric illusory art was created as early as 1934 by Swedish Artist Oscar Reutersvärd with the impossible arrangement of blocks shown here. I always considered all that type of stuff Escher Art, but apparently he wasn’t the first one with it.

It also seems that many of those impossible triangles and stairs and such have names like the “Penrose illusion” and “Mach’s figure”.  See them described here.