It drew 5.7 million visitors a year ago, according to the most recent TEA/AECOM Theme Index report, making it the 21st most-visited theme park in the world.
More than 25,000 visitors were on site when the fire broke out and many top rides, including the attractions " The Pirates of Batavia " and "Norway", were destroyed.
The blaze has consumed the show building for the Pirates in Batavia dark ride.
A huge fire has broken out at Europa-Park in the German town of Rust, the second most visited theme park in Europe after Disneyland.
"The park has been completely cleared", a police spokesman said.
The blaze reportedly started in a warehouse near "The Pirates in Batavia" attraction and spread quickly to other parts of the park, causing major damage.
Image Thousands of people escaped from the park safely
It required as many as 250 firefighters to extinguish the fire, which sends plumes of thick black smoke into the air.
The park opened and accepted guests Sunday, although portions affected by the fire remained closed. The police said that, according to preliminary data, there were no deaths or injuries.
Europa-Park's chief executive Michael Mack said on Twitter that it had been a "sad day" for the park.
The park is themed after the different regions in Europe and is located near Freiburg and the European Parliament in Strasbourg.
Founded in 1975, Europa-Park is Europe's second-most popular amusement park after Disneyland, attracting some 5.7 million visitors past year.