DISCOVER THE INDOOR INFRASTRUCTUREs and Activities OF THE region. ST-LÉONARD UNDERGROUND LAKE The spectacular and unusual St-Léonard underground lake is the largest such lake in Europe. Leisure centers Share moments with family or friends in the region's leisure centres. Swimming pools While living in Sierre, take advantage of the indoor swimming pools accessible to the public. Theaters Fitness Do you want to combine a training programme with personal coaching, or simply maintain your... Gyms Sierre has about ten gyms located at the four cardinal points of the city. Tennis Enjoy the tennis courts of the region. Patinoires The City offers two ice surfaces: a covered skating rink in Graben, and an open-air ice surface in...