What is the fine-grained topic of the following text: On the one hand an ice rink of 800 m² and on the other side a Snow Playground with an Ice Vertigo (downhill run for Zorbing balls and snow tubes), an Ice tower with a snow slide, Zipline tower, a carousel and a climbing mountain.The grand opening ceremony took place on Saturday, October 8th. Only return the topic.
Opening of a winter-themed amusement park