It might sound like a load of hot air, but an Austrian pilot has broken a new world record after flying a balloon deep into a cave in Croatia.

Ivan Trifonov successfully descended a hot air balloon to the bottom of the 206-metre-deep Mamet cave, which is located in Obrovac in the Velebit nature park.

The 25-minute flight was made using a specially designed, smaller than usual balloon that meant Trifanov had to sit on two gas cylinders framed by iron pipes rather than inside a traditional basket.

“I don’t believe this is going to be repeated by anyone ever again,” said Trifanov, who already holds four Guinness World Records for hot-air ballooning and is the first person to balloon over the South Pole and North Poles.

You can watch Trifanov’s spectacular flight, which was supported by the Croatian Tourist board, on the video below.