Welcome to The Museum of Non-Visible Art (MONA). Yes, you read that correctly. So what is this all about? Here's an extract from their site:
You can buy (the ownership rights to) an imaginary piece of art that doesn't physically exist. For example, pledge $20 or more to the cause and you will receive:"The Non-Visible Museum is an extravaganza of imagination, a museum that reminds us that we live in two worlds: the physical world of sight and the non-visible world of thought. Composed entirely of ideas, the Non-Visible Museum redefines the concept of what is real. Although the artworks themselves are not visible, the descriptions open our eyes to a parallel world built of images and words."