SS Rotterdam

You're standing by the Rotterdam, the big passenger ship moored at the quay in Katendrecht. Take a look at her profile. Notice anything? There's no ordinary funnel. Instead she has two slim exhaust pipes, set further back. In the middle of the ship sits a large deckhouse, exactly where you'd expect a funnel. Back then, plenty of people found that odd. Later it proved groundbreaking, and later cruise ships borrowed a lot from it.