Inside Sonny's condo in Seoul: Eterno Cheongdam

Residents are designed not to cross paths. Service staff slips through hidden back corridors, guests are received in a separate lounge, and a fingerprint is all that opens the door.

That is how Eterno Cheongdam looks after the 29 households in its single Cheongdam-dong tower, among them national soccer team captain Son Heung-min, who owns the most expensive home in the country.

High-end residences trade on exclusivity. Few do so as hard as the building that has topped Korea's property valuations two years running.

Under the government's publicly notified housing prices for 2026, released March 17 by the Ministry of Land, Infrastructure and Transport, a 464.11-square-meter unit at Eterno Cheongdam was valued at 32.57 billion won ($21.1 million), up from 20.06 billion won a year earlier, a 62.4 percent rise. It is the only home nationwide assessed at over 30 billion won. The unit was purchased by Son, whose family lives there, according to some news reports.

Eterno Cheongdam is a single building with four basement levels and 20 floors above ground, holding 29 units that range from 244 to 497 square meters. The first floor has a hotel-style lobby with ceilings reaching 10 meters. The second through fifth floors are 273-square-meter duplexes, and the sixth through 16th floors are single-level units. The 17th and 18th floors house two 273-square-meter sky penthouses, while the 19th and 20th floors form a single 497-square-meter super penthouse.

Built by Hyundai E&C, the complex is the first project in Asia by Spanish architect Rafael Moneo, winner of the Pritzker Prize, often called architecture's Nobel.

Every unit has a Han River view, achieved by arranging the exterior walls and balconies in a zigzag pattern across the single structure. Floor plans can be chosen by lifestyle, with kitchen-focused and living room-focused layouts. Standard ceilings rise 4 meters, and the duplex penthouses include voids of up to 7 meters.

The building is designed around privacy. Overlap between units is kept to a minimum to limit noise from neighbors above, below and to the side. Entry runs through fingerprint recognition, and security cameras and dedicated guards monitor the property. Residents and guests use separate lounges, while management, security and in-unit service staff move along a dedicated back-of-house route so they do not cross paths with residents.

Singer-actor IU, actor Song Joong-ki, Viva Republica founder and CEO Lee Seung-gun and Krafton CEO Kim Chang-han are among the residents.

The complex offers quick access to Yeongdong Bridge and the Olympic-daero, which link the areas north and south of the Han River. Galleria Department Store and the Apgujeong Rodeo shopping district are nearby, along with Cheongdam Elementary, Middle and High schools.

This series looks at the latest lifestyles of the ultrarich. — Ed.