Lotte World Tower is a 123-story, 555m skyscraper standing in Jamsil, Songpa-gu, Seoul. The structure topped out in 2016 and fully opened in April 2017, and it's held onto the title of Korea's tallest building ever since. The design came from the American firm KPF (Kohn Pedersen Fox), and the silhouette — tapering gently as it rises, like a brush stroke — was inspired by traditional Korean ceramics and calligraphy. You can spot it from almost anywhere in Jamsil, and it's essentially become the new landmark for southeastern Seoul.
The observatory, branded 'Seoul Sky,' spans floors 117 to 123. From B2/B1 you ride Otis's double-deck 'Sky Shuttle' elevator, which covers 600m per minute (10m/s) and gets you to the 117th floor in roughly a minute flat. That minute is a mini-attraction on its own — once the doors close, the walls turn into OLED screens playing a virtual tour past Seoul landmarks like Gyeongbokgung, the National Assembly, and Jamsil Stadium, so you barely notice the ride.
The 118th floor's headline act is the Sky Deck, a glass floor made of 45mm laminated tempered glass rated to hold a ton per square meter — up to 222 people at once. It's Guinness-certified as the world's highest glass-floor observatory, and standing on it with 478m of open air below is a rush you really need to feel in person. There are glass panels facing both the Namsan/Han River side and the Olympic Park side, so it's worth stepping on both. Floor 120 has the open-air Sky Terrace, and the top floor, 123, holds '123 Lounge,' Seoul's highest bar — great for a drink with the night skyline.
⚠️ Admission pricing trips people up: as of April 2026, adult entry to the Seoul Sky observatory runs about ₩33,000. If you'd rather skip the line entirely, there's a flat-rate ₩50,000 Fast Pass for any age — but it can't be booked online, only bought same-day at the on-site ticket counter. Regular tickets bought in advance through the official site or platforms like Interpark cut down your wait at the gate. If you want both dusk and night lights in one visit, arriving about an hour before sunset is the sweet spot.
The tower is just the centerpiece — the whole complex is a destination. The lower floors hold Lotte World Mall (shopping, cinema) and Lotte World Aquarium, one of the world's largest indoor aquariums, while the upper floors house the 6-star Signiel Seoul hotel and Lotte Concert Hall. To get there, take Subway Lines 2/8 to Jamsil Station Exits 1/2, or Lines 2/9 to Sports Complex Station — both connect underground straight into Lotte World Mall, so rain isn't a problem.