Just when theme parks are starting to get more otherworldly, taking on themes from Star Wars to Harry Potter, one German attraction is creating lineups galore by offering something relatively more primal.

In this case, the draw features water, water and everything else to do with water. And you'll find a giant reservoir of nature's most essential fluid in a swimming pool the size of more than five NFL field-sized fields all indoors at the recently-opened Rulantica indoor water park.

3 Exotic Lagoons

The size of the aquatic structure alone sounds breathtaking, but there's more. The facility boasts 17 waterslides, some with suspenseful vertical drops and others made for inner tubes and other inflatables. Wandering observers can stumble upon a number of finds throughout the Rulantica complex from exotic-looking lagoons to swim-up bars.

Located in the idyllic town of Rust, right by the German-French border, the park is the brainchild of the enterprising Mack family. It's the same household that made a killing with its monumental Europa-Park that first opened in 1975 and annually draws nearly six million visitors. Among them, a few regulars who knew the Macks suggested the group create a more marine-based equivalent.

2 Watery Paradise

The family liked the idea and after 20 years of planning and creating mockups, the shovels finally hit the dirt late in 2016 to make Rulantica a reality. Boasting an interior that's more than 300,000 square feet, the structure cost nearly US $200 million to build. Admission to the watery paradise is roughly US $42 per adult and about US $39 for kids and teens.

Also going into the design are several self-sustaining features, such as the 3,000 solar panels perched outside and the elaborate filtration infrastructure capable of recycle up to 80 percent of liquid waste. And while it's meant to entertain fun-loving humans, animals residing nearby have also warranted attention such as a hideaway corridor for bats. Builders also added a facility for bees that produce the extracted honey currently available at one of the Mack hotels near Rulantica.

1 Nordic Roots

The facility shies away from imitating an equatorial locale, preferring to stick to its more Nordic roots, with roughly 20 themes throughout the complex reflecting that image. But what waterpark would be complete without a few mermaids and even an octopus named Snorri?