서울

This is backside of Namdaemun Gate (남대문), one of the Eight Gates of Seoul. As per Wikipedia: Officially known as the Sungnyemun, is one of the Eight Gates in the Fortress Wall of Seoul, South Korea, which surrounded the city in the Joseon dynasty. The gate is located in Jung-gu between Seoul Station and Seoul Plaza, with the historic 24-hour Namdaemun market next to the gate. See: en.wikipedia.org/wiki/The_Eight_Gates_of_Seoul en.wikipedia.org/wiki/Namdaemun

Was this photo taken in 1910, when the entire Korean Peninsula had become another colony of Japan?

Myeongdong Cathedral ,Cathedral Church of the Virgin Mary of the Immaculate Conception 천주교 서울대교구 주교좌 명동대성당 completed 1898.

The building in the background is the Gyeongseong Post Office (a.k.a. "Old Central Post Office") in Seoul, Korea. Built in 1916, it would be shelled, burnt out and gutted, during the Korean War, and then demolished in 1957.

Gwanghwamun Gate As per Wikipedia: Gwanghwamun (Hangul: 광화문; Hanja: 光化門) is the main and largest gate of Gyeongbokgung Palace, in Jongno-gu, Seoul, South Korea. It is located at a three-way intersection at the northern end of Sejongno. As a landmark and symbol of Seoul's long history as the capital city during the Joseon Dynasty, the gate has gone through multiple periods of destruction and disrepair. Restoration work on the gate was finished and it was opened to the public on August 15, 2010. See: en.wikipedia.org/wiki/Gwanghwamun