Lotte Aquaslон draws 1,000 competitors to swim Seokchon Lake, climb World Tower

Lotte Mulsan announced Sunday that the 2026 Lotte Aquaslон, a race combining an open-water swim across Seokchon Lake in Jamsil and a stair climb up Lotte World Tower, was held successfully.

Launched in 2022, the Lotte Aquaslон has been officially organized and sanctioned by the Korea Triathlon Federation since 2023. The event pairs a 1.5-kilometer open-water swim — two laps around the east lake of Seokchon Lake — with a sky run up 2,917 stairs to the 123rd floor of Lotte World Tower. Now in its fifth year, the competition expanded its field to about 1,000 participants. Registration closed in just 10 minutes.

Eighty-six competitors took part for the third consecutive year. The field included Cha In-taek, 79, the oldest male finisher, Kim Pyeong-sun, 68, the oldest female finisher, and various groups such as married couples and sisters competing together. Kim Wan-hyeok won the men's division in 42 minutes and 59 seconds, while Kim Tae-hyang took the women's title in 46 minutes and 58 seconds.

Cha, the oldest competitor in the event's history, said he came "to taste the waters of Seokchon Lake and conquer the 2,917 stairs of Lotte World Tower as I turn 80," adding that he was able to finish comfortably thanks to years of health management through more than 100 triathlons.

Kim Wan-hyeok, who also won the 2024 edition for his second title overall, said the lake was so clear he could see the bottom, calling the water quality "the best compared to anywhere abroad." He added that he struggled around the 60th floor but was thrilled to finish with a faster time.

Three Lotte affiliates — Lotte Mulsan, Lotte Holdings and Lotte World — along with Songpa-gu, environmental firm Gens and the Green Future Foundation have worked together to improve Seokchon Lake's water quality. Since 2021, they have carried out a water-quality improvement project using eco-friendly photocatalyst technology, and the lake's transparency has been maintained at more than 2 meters for the past five years. The lake has also received first ratings across most water-quality environmental standards, and passed coliform bacteria and turbidity tests conducted by the Korea Triathlon Federation in June.

Jang Jae-hoon, chief executive of Lotte Mulsan, said the Lotte Aquaslон "has established itself as a unique sporting event symbolizing the harmony between the environment and the urban landscape, held on the now-pristine Seokchon Lake after years of continuous water-quality improvement."