Tim Cook, CEO of US tech giant Apple, has been spotted in Slovenia in recent days. He visited the famous Postojna Cave and Ljubljana.

Cook took part in a cave tour called In the Footsteps of Luka Čeč, which takes the visitors along the trails of the first cave explorers.

As part of the tour, he also visited Pivka Cave and Black Cave, the Postojna Cave operator said on 7 September. Cook was interested in learning more about the cave's most famous inhabitant, the olm or "human fish" as it is known in Slovenian, as well as about the history of the cave, according to the company's press release.

Cook was also received by the operator's directors Kaja and Lana Batagelj.

"Everyone in the world should see this. Truly non describable with words," Cook wrote in the Postojna Cave visitors book. He thanked the staff for "the most incredible tour, one of a kind".

Apple CEO Tim Cook meets the directors of the Postojna Cave operator, Kaja and Lana Batagelj, during his visit to the famous karst cave. Photo: Postojna Cave

One of the biggest tourist attractions in the country, the Postojna Cave has long been a place attracting high-profile visitors, from emperors of the Austro-Hungarian Empire to modern-day heads of state and other famous personalities.

A few days ago Cook was also spotted at several places in Ljubljana, which elicited speculations about the nature of his visit to Slovenia.

"When you randomly find Tim Cook walking into random coffee shop in your small European country. What are the chances," one of the locals wrote in a post on X on 3 September after spotting him at a Ljubljana City Museum café.

Another local informed a media outlet that he saw the Apple CEO and took a picture with him at a restaurant at Ljubljana Castle.

He is believed to have been visiting informally. Before making a stop in Ljubljana, he visited the Venice Film Festival. According to the city's news portal Ljubljanainfo, neither the Ljubljana municipality nor the Ministry of the Economy, Tourism and Sport were informed about his visit.

Cook joined Apple in 1998 as a senior vice president for worldwide operations, and then as executive vice president for worldwide sales and operations.

He took over as CEO in 2011, after Steve Jobs, who died from cancer later that year, resigned.