Chicago native Lukasz Bokun grew up in the company of skyscrapers — not mountain ranges. But that never stopped him from setting his sights high on the summits of the world’s tallest peaks.

“I have always had mountaineering in the back of my mind,” Bokun said, explaining that he established a lifelong curiosity for mountaineering at a young age after spending countless hours listening to his father recount stories of the climbing expeditions of his youth.

Now 24 and working as a financial analyst, Bokun plans to explore this passion for peaks by tackling some of the highest and most difficult mountain expeditions in the world, including the Seven Summits — the highest mountain on every continent.

Earlier this year, Bokun crossed one of the seven off the list when he successfully summited Africa’s 19,340-foot Mount Kilimanjaro.

From here, he plans to follow the Seven Summits list compiled by European Mountaineer legend Reinhold Messner, which includes two peaks in Asia and none in Australia. Still ahead are Mount Vinson in Antarctica, the Cartensz Pyramid and Mount Everest in Asia, Mount Elbrus in Europe, Mount McKinley in North America and Mount Aconcagua in South America.

To prepare for the remaining six, Bokun will also climb several smaller peaks. In April, for example, Bokun headed to Washington State to complete a training course on Mount Rainier, a massive and technically challenging 14,411 feet volcano southeast of Seattle.  This summer he will attempt California’s 14,505-foot Mount Whitney before attempting his second of the Seven Summits — Mount Elbrus, a 18,510 peak in Russia’s Caucasus mountain range.

As Bokun attempts these rigorous expeditions, he has prepared to face numerous physical challenges. Proper hydration, for example, is a key factor for successful mountaineering, especially on peaks surpassing 10,000 feet where altitude starts to take a serious toll on the body. To ensure Bokun is prepared, Polar Bottle sent the climber several water bottles that will keep him hydrated from base to summit.

In total, Bokun expects that the series of expeditions will take close to four years. Though he is surrendering much of his mid-20s to the world’s greatest peaks, Bokun says the glory of completing the Seven Summits far outweighs the sacrifice.

“It will be a true test of my character and abilities,” he said, of facing the Seven Summits. The elation from actually finishing them, however, he expects will ”be out of this world.”