Sugangjae (Hanja: 壽康齋; English: the House of Health and Longetivity) is located east from Seokbokheon Pavilion in the Nakseonjae Area, Changdeokgung, one of Five Jewel Palaces of the Joseon Dynasty. It is the place where Empress Sunwon of Andong Kim Clan, Grandmother of King Heonjeong - 24th Monarch of Joseon Dynasty and Consort of King Sunjo - 23rd Monarch of Joseon Dynasty resided. The Last Princess of Korean Empire, Princess Deokhye a.k.a Countess Tokue Sou (Tokue is Japanized name for Princess Deokhye) was died on April 21st 1989 in this hall.
It was built in 1785 and is notable for the Chwiunjeong Pavilion behind it, which was built in 1686. It is renovated in 1848 and turned into the quarters of Empress Sunwon, the grandmother of King Heonjong.
Going on to the 20th Century, Princess Deokhye was invited by the Government of the Republic of Korea for homecoming in January 26th 1962. She cried while approaching her motherland, and despite her mental state, accurately remembered the court manners. She lived in Nakseonjae Grounds with Crown Prince Uimin and Crown Princess Masako Nashimoto a.k.a Yi Bang-ja (Bang-ja is Koreanized name for Masako), their son Prince Gu, his wife Julia Mullock, and Mrs Byeon Bok-dong, her lady-in-waiting. She spent final moments in Sugangjae until her demise on April 21st 1989, in the age of 76. She was buried at Hongyureung Imperial Tomb, Namyangju, Gyeonggi Province.