cd's post reminded me that the Hyatt in Minneapolis is in a former mill, right by a waterfall. Hotel itself seems pretty Hyatt-y once you're inside however.

For your Hol Inn points, think of the Crowne Plaza St. James in London. We stayed there in August (two nites free - thank you Priority Club!!). A very pleasant property about a five minute walk up from Queenie's joint. (With the typical British wndow treatments swathed in floral fabric).

In Wisconsin, there are some Best Western hotels with 'theme' rooms, I believe. Also, have read here and there of motels with converted railroad cars. Do a google with "theme hotel rooms" and "railroad car hotel rooms" and you'll get quite a few hits.

Also, google for "lighthouse hotels" We have not stayed in one but I know they're around.