Number 18 on my 30 Before Thirty list: done.
It was beautiful, but SO impractical. There was a lot of client/architect drama between Edith Farnsworth and Mies van der Rohe. Ms. Farnsworth claimed that the house was unlivable (it had almost no storage), and the price skyrocketed as work progressed. Mies took the stance that it was a getaway house and you should have little more with you than a change of clothes, therefore it doesn’t need to be practical.
Still, was amazing. It’s constantly under threat of flooding, so go see it sooner than later if you’re able.