Jiwon Park (JP)
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It was amazing to see in person a bunker built during the Soviet era. The staff were friendly or tried to be friendly.
The restrooms are clean and the atmosphere feel as go down to the bunker is very inviting. It's a great place to take pictures, and in fact, visitors from many nationalities attended the English tour.
However, it was very difficult for us visitors to climb from the bunker to the ground. (I think the people who used this bunker during the Soviet era probably had a similar difficult time.)