Swimming

Outdoor waterpark for adults and children including water slides over 25 meters tall, surfing, beach, kiddy splash pools, and giant wave pools.

If you’re looking to hang ten and ride some waves in a relaxed, beginner-friendly setting, then this indoor wave pool is a suitably fun plan B. All you need is a bathing suit and a half-decent sense of balance (or if not, a good sense of humor when you fall into these indoor waters), and the facility will provide you with the rest.

The biggest open-air water park in the city, Happy Water Rubik’s Cube is worth the trip to Fengtai District. The many rides inside, including flumes, raft rides, and a wave machine, will help you forget just how hot it is outside. The park is fitted with a water filter that operates 24 hours a day.
Daily 10am-6pm. RMB 230 (adults), RMB 180 (kids between 1.2m and 1.5m), Free (kids below 1.2m).

Belonging to Chenjinglun Middle School and now 20 years old, this indoor pool remains clean and busy, and has a depth of 1.4-1.6 meters. Many locals and their children learn to swim here. 
Daily 10am-9pm. RMB 50 (adults）

Freediving China is located in Beijing, but also organizes trips both inside and outside of China.

Fulicheng's clubhouse contains a gym/fitness center, pool and an attached Cantonese restaurant.

Located in a Shunyi residential neighborhood, this fitness club mainly trains expat teens in swimming and other forms of exercise to improve their physiques.

Xuanwu District might seem a bit of a hike for eastsiders, but this weekly poolside buffet at the Doubletree by Hilton makes the trip well worth it. Every Sunday, the hotel’s rooftop garden terrace (adjacent to its sizeable, covered pool where you can swim to your heart’s content) is transformed into a serene retreat replete with a buffet and all-you-can-drink alcohol for a most agreeable RMB 158 per head (kids under the age of 2 get in free, otherwise it’s half price).