Off the beaten path art tourism

I was reading Peter Schjeldahl's book of collected art essays the other day. (Link to the Amazon page for the book). There is a chapter on the Chinati Foundation's home in Marfa, Texas, founded by Donald Judd. (Chinati Foundation webpage). It sounds like a magical place. I was reminded of my trip to Naoshima, Japan last year which I blogged about here. These are places most of us would never dream of visiting if they weren't filled with amazing art of one kind or another. Schjeldahl mentions Brancusi's home of Târgu-Jiu as another locale that could be added to that list. (Wikipedia page for Târgu-Jiu).
I started to wonder where else there might be that would qualify as this kind of wacky art tourism? I think it doesn't count if it's a great museum in a town that maybe isn't so popular (like Detroit or Toledo, Ohio). I also thought about places like Storm King in upstate New York. But places like Storm King and DIA/Beacon are in such easy proximity to a major metro area, it's hard to call them off the beaten path. Same deal with Taliesin and Taliesin West. So, let's make a list. Where else do you know about that is in the middle of nowhere, and the only reason to go is that it has remarkable art?

Naoshima, Japan
Marfa, Texas
Târgu-Jiu, Romania
?