Surfers invented modern skateboarding by riding through empty pools during a drought, which proved more thrilling than forgoing showers in favor of cat baths. Eschew unnecessary water with today's Groupon: for $25, you get five skateboard or BMX sessions at 4 Seasons Skate Park (up to a $55 value).

At 4 Seasons Skate Park of Milwaukee, an abundance of ramps and rails allows skateboarders, BMX riders, scooters, and in-line skaters to practice tricks and techniques in a safe, sheltered environment. After strapping on helmets, participants can drop into half pipes, glide across grind boxes, catch sweet air in clover-shaped bowls, and fly down small flights of steps before occasionally pausing to make way for a family of passing ducklings. Graced by celebrities such as Tony Hawk, Lil Wayne, and the ghost of Groucho Marx, 4 Seasons' bevy of progressive ramp designs and a combination of vertical and street courses accommodate customers of beginning and advanced skill sets alike. Skaters can rent gear for an additional fee and drop by during scheduled rider hours.