Short mono rail trip up to the deck takes about a min or so. It is more like a tram i guess. Can see the North Korean side but nothing is amazing or great. I thought it was rather boring. HOWEVER if you are in DMZ, gotta see it because it is probably the one of top three places to visit.

This large and optimistically named "peace" observatory is located within the civilian restricted zone, so you must visit as part of the Iron Triangle Battlefield Tour. You gain access to the top of the observatory by taking a short monorail ride . Once there, there are observation areas with binoculars so you may see over to the DMZ. Inside there is a theatrette where we had to sit and watch a short documentary, unfurtunately it was all in Korean, so of zero value to an english speaker. After that we were allowed to wander around and look, however you are not allowed to take photos towards to DMZ area or military installations (you can see a military checkpoint and fencing). You can also see that there is no sign of human habitation in the DMZ, quite eerie. It was a very rainy and cloudy day so we could not see much but it was still interesting to imagine what might be there. Also on sight there is a small museum (all in korean) and a shop selling local foods and some north korean items.