Options for Monday
The National Museum of Korea in Yongsan opens on Mondays and has free permanent galleries. Check its current hours, regular gallery-closure dates and holiday notices before visiting, particularly around Seollal (Korean Lunar New Year) and Chuseok (the autumn harvest holiday).
MMCA Seoul, beside Gyeongbokgung, also opens on Mondays. Its published hours are 10:00–18:00 on Monday, Tuesday, Thursday, Friday and Sunday, and 10:00–21:00 on Wednesday and Saturday. It lists closures on 1 January, Lunar New Year's Day and Chuseok. Admission fees depend on the exhibition.
Gyeongbokgung normally opens on Mondays and closes on Tuesdays. Holiday exceptions and seasonal hours need a separate check. “Seoul has five palaces. Which one should I actually visit?” compares the palaces.
Check other venues individually
A Monday closure at one museum does not establish another museum's schedule. Check the War Memorial and each palace or gallery on its own visitor page. Check the last-entry time as well as closing time.
For rain, choose an indoor exhibition that interests you and confirm that it is open. Palaces include outdoor walking, so an open palace does not provide the same shelter as a museum.
Evening visits and admission
MMCA Seoul offers free entry during its Wednesday and Saturday late opening, from 18:00 to 21:00, and on the last Wednesday of the month. Check the exhibition page for other admission conditions. The National Museum also publishes evening opening hours on its visitor page.
A museum's free permanent galleries do not establish the price of a special exhibition. “Palace and museum tickets” explains the ticket checks to make before visiting.
