Time Out says
Gear up for the season at Decathlon. Originally from France, the retailer offers incredibly affordable sportswear and gear for more than 70 sports, including popular summertime activities such as snorkelling and scuba diving. The huge flagship store in Mong Kok occupies the entire basement of Grand Plaza. Aside from shopping for various sporting essentials, you can also make use of some of the free indoor facilities – all in cool, air-conditioned comfort.