A "casino" (little house) is a place for social amusement and get-togethers, either public or private. The East coast used to have many clubs and assembly places called "casinos," often on the seashore. Gambling Casinos are a kind of casino.
Have you ever tried tennis on a grass court? I have. It's fast and the ball skids low. You skid, too. It's good fun.
Sipp, our American architectural expert, says that Newport, RI is basically the birthplace of Shingle Style. Here's his pic of the courtyard of the shingle-style Newport Casino, now the International Tennis Hall of Fame.