Carl Barks colored drawing Which Disney Theme Park is This?

Generally, I prefer comic book artwork by Barks in his storytelling prime to Duck paintings and other artwork by Barks the retiree. This colored drawing is an exception. It was created in 1983 as an idea sketch to the cover for a proposed Disneyana book. The book was never published, and Barks reworked the idea to the oil painting "In Uncle Walt´s Collectery". The content in the drawing is taken from the "Land Beneath the Ground" story (Uncle Scrooge 13), featuring the subterranian creatures Terries and Fermies. In the composition, everything points to the five Ducks. The drawing was first published (as a tiny and murky b&w scan) in Carl Barks Library Vol. VI, p.99. A much better published version in Egmont´s Carl Barks Collection - The Paintings Book p. 266.