Ivan Trifonov has gained his fifth Guinness World record by becoming the first man alive to accomplish an underground hot air balloon flight, supported by the Croatian National Tourist Board.

Trifonov, a seventy-year-old Croatian national originally from Austria, descended to the bottom of and successfully exited the 206 metre deep Mamet Cave (Jama Mamet) in Croatia in an unprecedented venture.

The daring undertaking took place ten years after Felix Baumgartner successfully BASE jumped into the same pitch-black cave and was backed by the Croatian National Tourist Board to raise awareness of the opportunities for active tourism in the country.

The historic balloon flight, which was inspired by the visionary Jules Verne’s book Journey to the Centre of the Earth, lasted about 25 minutes, from its departure to the landing at the bottom of the Mamet cave and successful return to the surface.

For this unique underground flight, Trifonov had to use a specially designed balloon, which was smaller than a usual hot air balloon and meant the pilot sat on two gas cylinders framed by iron pipes rather than inside a basket.

“This was a once-in-a-lifetime opportunity for me to visit Tartarus (hell), right?” Trifonov joked.

“It has been an incredibly difficult project.

“You must have the right balloon, the right weather, and the right support.

“I don’t believe this is going to be repeated by anyone ever again,” he continued.

The experienced hot air balloon pilot has already broken four records in the Guinness Book of Records: for hot air ballooning over the South Pole, the North Pole, and the Mediterranean Sea, as well as for being the first man who stood, dived and flew over the North Pole all within 12 hours.

The Croatian National Tourist Board hopes the incredible video of Trifonov’s challenge will inspire other active tourists to visit Croatia and experience the country’s beautiful landscapes and wealth of activities to suit anyone with an adventurous spirit.

The Mamet Cave is 206 meters deep and is shaped like an inverted funnel, with an impressive entrance that stretches approximately 60 meters in diameter.

The first written records of the cave, which is located in Obrovac in the Velebit Nature Park, date back to 1929.

The first descent to its bottom took place on July 5th 1968, when topographic mapping and aerial photography were performed, to produce a map of the site which is still being used today.