Designs have been unveiled for an ambitious indoor waterpark set to open as part of the 17bn euro (£15bn, US$23bn) Gran Scala leisure city under construction in Aragon, Spain.

Designed by architect Cent Alantar, the waterpark will be located within the Spyland theme park, and will feature both indoor and outdoor rides.

Attractions will include water slides, pools, waterfalls and “secret underwater passageways, with historic theming based on periods such as ancient Rome and Egypt, and the Renaissance.

The building will be shaped like a drop of water, with a centrepiece consisting of a tall twisting waterslide with Renaissance theming, set against an aquarium backdrop.

There will also be a private relaxation area with a Roman bath theme, including spa pools, mud baths and massage.

Aquantica is on track to open in 2013.