First stop today was Jinpo Marine Theme Park, which is part of the Gunsan Modern History Museum.
Gunsan is about a 2-hr bus-ride south of Seoul, and the museum is about a ten-minute bus-ride or 30-minute walk from the intercity bus terminal, so the museum is doable as a daytrip from Seoul on public transport. The museum is closed on Mondays - which is something that would have been good to know before I came down yesterday! Fortunately, I had planned to stay the night in Gunsan, so I was able to visit it this morning before leaving town.
The main element of the Theme Park is the WW2 LST Wi Bong - formerly USS LST-876 - originally completed in January 1945 and served 14 years in the USN before being transferred to Korea. The LST is mounted on blocks on the mudflats in the fishing harbour area of Gunsan. Access is via the bow door ramp, and the entire tank deck has been fitted out as a museum - to the extent that if you didn't already know, you probably wouldn't realise you were on a ship. The museum covers a little about the ship itself, but is mainly about the Korean Navy, generic naval history, and other maritime themes. In the port passageway (outboard from the tank deck) there are additional galleries, while the starboard passageway is presented as accommodation/ablution spaces, and is the only part of the museum that resembles a warship. The upper decks and superstructure were not open - however I suspect that was because of the ice hazard early in the morning, and if you go in summertime (or even in the afternoon) it may well be open. There were certainly external stairs added to the ship providing direct access to the upper deck from the shore.
The ship itself seemed to be in reasonable condition, although the paintwork was much better on the side facing the shore, than the side facing the harbour.
All-in-all, provided you can get access to the upper deck, it is a very similar museum to her sister ship Un Bong at the deceptively similarly named Gimpo Marine Park (about 200km to the north)
Entrance to the museum cost approx AUD$1. There was no sign of a shop.
On the shore adjacent to Wi Bong was an equipment park, with several tanks, guns, aircraft etc, and the 250-ton Coast Guard cutter Manison, which didn't appear to be open to visitors.