Peter Eisenman's Berlin/Holocaust memorial Light and Shadow. I like the way the structure of the building creates strong impressions of light and dark. Also the juxtaposition between the natural and man-made forces interests me.
The squiggle lines created with the markers looks very effective. This is a great example of drawings do not need to be perfect to look effective. In some cases it looks much more effective when the marker technique is more messy and unforced.