Additive Approach

In this exercise I tried to create circular and spiraling voids using square and rectangular blocks.
Isometric: The vertical void is hard to make out at first from this perspective, but it's in the forground with one of the openings to the horizontal void to it's right

Perspective Elevation: This view clearly shows the horizontal void

Perspective Elevation, Top View: Looking down through the vertical void

Immersive Perspective: Inside the horizontal void looking out

Immersive Perspective: At the top of the vertical void looking down