The Sun Deck is the top floor and the roof level of Strangetown Hotel in The Sims 2. Here you can find some tables and deck chairs to sunbathe (although only affects to sanity)

The elevator stops here, and it's the highest floor. Below, in ascending order is the Penthouse, 2nd Floor Lobby and the Main Lobby. The Sun Deck remains absent from the main storyline until the goals nearing the end of the game, where your sim must go there in order to get Lord Mole to stop chewing at the power lines for Optimum Alfred's TV antenna.

The game finale, or the final boss battle, also occurs on the Sun Deck, when Optimum Alfred launches an attack on Strangetown with the help of his accomplices. The battle ends when your sim, in the Ratticator costume, manages to stun Alfred, and push him into the pool causing him to malfunction.