REMOVE

1. fences
2. trees
3. hills
4. towers (building divisions)
5. buildings (structures)

WHAT

1. Visual Works (hierarchy n … (1)
2. atmospheric perspective (1)
3. barns (1)
4. black-and-white film (1)

More 

WHERE

1. New Windsor, Maryland (1)

WHEN

1. 1967 (1)
2. ca. 1967 (1)