The title of the biggest waterpark in Portugal is often contested between Aquashow Park and Slide & Splash, both located in the Algarve region. As of 2026, Aquashow Park (near Quarteira) is widely regarded as the largest and most comprehensive, especially following its recent expansions. It is unique for being both a water park and a theme park, featuring a massive "Water Coaster"—one of the largest in the world—and the 32-meter high "Free Fall" slide. It also boasts a significant indoor water park area that allows for year-round operation, a luxury the other parks lack. Slide & Splash (near Lagoa) is its primary rival, covering roughly 25 acres and famous for its "Big Wave" and "Kamikaze" slides. While Slide & Splash is often cited as having the best variety of slides for pure adrenaline, Aquashow’s integration of hotel facilities, indoor zones, and traditional theme park rides gives it the edge in terms of total square footage and overall "mega-park" status within the Iberian Peninsula.