What attracts me most about the TARDIS concept is being able to witness the “silent” moments of the universe; for example, watching the birth of a star or the collision of galaxies from afar.
When it comes to Van Gogh, I'd be curious not just about his paintings, but what he truly felt when he looked up at the night sky. As for Narnia, what captivates me is the idea that the world “calls” to children; as if, if you're in the right place at the right time, the door opens for you. 😉