Complex sentence: Completed in 1972, "Cloud Fortress" was located in a minor plaza between buildings 4 and 5 that gave access from Church Street to the large Austin J. Tobin Plaza central to the complex of World Trade Center buildings.
Split into simpler sentences: Completed in 1972, "Cloud Fortress" was located in a minor plaza at Church Street between buildings 4 and 5. The minor plaza gave street access to the large central Austin J. Tobin Plaza between the complex of World Trade Center buildings.