Larry,
 
     Many interior structures at Fort De Chartres State Historic Site in
     southern Illinois (outside the town of Prairie du Rocher) are
     represented with low (ca. 1-2 ft high) cobble walls capped with
     concrete (these date from an early effort at partial reconstruction of
     the mid-18th-century French fort).  There presumably are true stone
     foundation remnants below the visible representations.  This was also
     done years ago for segments of the curtain walls, but most of those
     partial representations have now been replaced with full-height
     reconstructions.
 
     I am also aware of an analagous situation at the site of Fort Knox II
     near Vincennes, Indiana.  The location of the former wooden stockade
     is represented by upright truncated timbers (probably telephone poles)
     that stand about 2 feet high.
 
     If you need information about contact persons, please feel free to
     call or e-mail me directly.
 
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