Translation:Let's go hiking in the museum.
I do not know, it's just a sentence or it has some (hidden) meaning. Is here any Korean could explain it?
Well the national museum of korea in seoul has some beautiful gardens surrounding it. Maybe someone would consider walking there hiking?
Although there are outdoor museums, no one says let's hike in the museum. It is an uncommon sentence.
That word is used for objects, such as a bag. Not sure if they're interchangeable.
I think it's maybe because you didn't add the 'go' to 'let's go' and also cuz you didn't bend the word hike to hiking :p
My father in law is korean and i remember him usingthe word hike when i would have used the word walk, took me awhile to understand what he ment, might be a similar translation error.
It's probably just another weird sentence. The hanja for 등산 is 登山, which literally means mountain climbing.
There are some museums which are so large that it would be quite a "hike" to visit all their exhibits. But in American English hiking has an outdoors connotation.