The building began as something far more ambitious. In 1988, architect Hiroshi Hara conceived the "City of Air" project: four interconnected towers rising above the Umeda central business district, near the banks of the Yodo River. Hara drew on two conceptual threads. The first was the Grande Arche in Paris, with its bold hypercube geometry. The second was more poetic -- a vision of a floating city, where open-air gardens and viewing decks would hover above the Osaka skyline, contrasting with the opaque ceramic atrium grounding the structure at street level. Then the Japanese economic bubble burst. The collapse gutted the project's financing and slashed the plan from four towers to two. What survived, though, kept the most daring element: that connected rooftop platform suspended between the towers like a gateway to the clouds.

The construction method alone would have made the building famous. Takenaka Corporation erected the twin towers using reinforced concrete, building them in parallel until they stood complete but separate. Then came the audacious part. The circular Floating Garden Observatory -- the structure that would bridge the two towers at their summit -- was assembled on the ground between them. Using a system of hydraulic lifts, workers raised the entire platform skyward, slotting it into place at the 39th and 40th floors. The glass-layered escalators and elevator bridges that now carry visitors between the towers in dizzying open-air crossings were installed using the same lift-up method. It was the first time this technique had been used in any building project in the world. The Umeda Sky Building opened its doors on March 25, 1993.

The rooftop Kuchu Teien Observatory -- the name translates to "Floating Garden" -- is the building's crown. Spanning the two towers at 170 meters above street level, the two-floor observation deck offers unobstructed panoramic views across the Osaka skyline, from the dense urban grid of Kita-ku to the distant ridgelines beyond Osaka Bay. An open-air rooftop ring allows visitors to walk the perimeter with nothing but sky above. Inside, Cafe Sky 40 provides a more sheltered vantage point. Along the railing, the Fence of Vows has become a ritual stop for couples, who attach padlocks as tokens of commitment. At street level, the building's base houses the Shin-Umeda City gardens, where walking trails, water features, and an urban vegetable garden occupy the ground that was once slated for the third and fourth towers.

Beyond its architectural fame, the Umeda Sky Building functions as a working commercial hub at the center of Osaka's busiest transit corridor. Osaka Station and Umeda Station -- among the most trafficked railway stations on Earth -- sit within walking distance. Sekisui House, the building's developer, maintains its corporate headquarters here. The East Tower alone houses an international roster of tenants: Mazda keeps offices there, AstraZeneca runs its Japanese and Asia-Pacific operations from its floors, the German consulate-general occupies the 35th story, and the celebrated game studio PlatinumGames -- creators of Bayonetta -- works from within the building's walls. It is a place where diplomacy, industry, pharmaceuticals, and video game design share elevator banks.