The Colour of Magic : Discworld: The Unseen University Collection by Terry Pratchett

On a world supported on the back of a giant turtle (sex unknown), a gleeful, explosive, wickedly eccentric expedition sets out. There's an avaricious but inept wizard, a naive tourist whose luggage moves on hundreds of dear little legs, dragons who only exist if you believe in them, and of course THE EDGE of the planet...
Binding: Hardback