OK, I had some spare time, so out came the World Atlas. After flipping to the page on Korea, I ran my finger along the coast line until, THERE IT WAS, Sinanju! It is on the coast, at the tip of an inlet. It can be found about 100 miles N.W. of Pyongyang.
Most maps do not show Sinanju (at the insistence of Chiun), but do have Sinuiju. Sinuiju is just North of Sinanju, but it is a shameful place, without the beauty and dignity of Sinanju. The "Horns of Welcome" were not mentioned.
If you are rusty on geography, Korea is across the Sea of Japan, across from, well, Japan. You can contact the American Red Cross for information on Submarine transportation in and out of N. Korea. Warning: Sinanju does not welcome tourists!