The Rulantica site has a total area of 450,000 m2 (4,800,000 sq ft), and a maximum capacity of 5,000 visitors per day.

[6] According to Badische Zeitung, the total construction cost was then said to be about EUR 150 million,[6] and has one of the largest wooden roof structures in Europe.

[5] The pylon that supports the wooden roof structure is made of spruce wood and has a mass of 50 t.[7] Rulantica has a total indoor volume of 300,000 m3 (11,000,000 cu ft).

[8] About 25 per cent of the electric energy needed for Rulantica is generated with solar cells installed in the car parks as shadowing.

[11] The Krønasår hotel is modelled on a museum of natural history[12] that features various exhibits based on fictional Rulantica characters,[11] but also non-fictional exhibits like the Wiking Saga that was used by Burghard Pieske [de] to cross the Atlantic.

[16] In April 2014, the Rulantica brand was registered by Europa-Park GmbH & Co Mack KG.

Back then, German magazine Parkerlebnis speculated that Rulantica could be an addition to Europa-Park, likely an entertainment show or a relax ride.

[18] On 8 July 2014, Europa-Park GmbH & Co Mack KG announced that Rulantica would be a water park.

[19] Eventually, the Rulantica project was approved in March 2016, and construction of the Krønasår hotel bagan in May 2016.

[28] In June 2021, several new outdoor areas were opened, with a combined total size of 9,000 m2 (97,000 sq ft).

The ship's boy Fin learns from the mermaid Kailani that taking the natural spring water from Rulantica would cause the island's demise.

The novel tells the story of two orphans who are on an adventure trip to the Nordic island of Rulantica.

[33] The first volume "Die verborgene Insel" was originally published in 2019;[34] the English translation, "Hidden Island", edited by Marielle Sutherland, followed in 2021.