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