If you are like me and enjoy (usually) the sights and activity at airports, then sometimes it is good to get out of the lounge and do a little exploring. In addition to visiting eight different Priority Pass lounges at ICN, the lounge crawl showed me features of ICN that had been overlooked in the countless other times that I’d flown to or through this airport.
Other posts about the Great ICN Priority Pass Lounge Crawl:
The Great Seoul/Incheon (ICN) Priority Pass Lounge Crawl, Part 1 – Main Terminal
The Great Seoul/Incheon (ICN) Priority Pass Lounge Crawl, Part 2 – Concourse A
Main Terminal 4th Floor (4F)
The concourse level at ICN is a beehive of activity. 
There is a huge sign on the 4th floor advertising transfer amenities. Unfortunately, most are too rushed or concentrating too much on travel issues to see the sign and investigate. 
Access 4F via elevators or escalators to the lounges and transit hotel. 
Once on 4F, it is like another world.
Tranquility reigns. Possibilities are revealed.
The Korean Culture Museum, which explores the 5,000 year history of Korea, is located in the center of the 4F complex.
The east and west ends of the 4th floor boasts a slew of attractions to pass the time including, a Heineken Bar serving beer, soft drinks and pastries, a movie zone with comfortable chairs and a wide screen TV showing non first-run movies, skincare and massage services, and showers. 
I was amazed to learn that ICN has an observation deck, Airstar terrace, that is accessed from the middle of 4F. I did not visit on this trip.
Concourse Level
Even those who stay on the concourse level can find some interesting activities.
The meeting point for free transit tours is at a kiosk near Gate 29.
A series of free sightseeing tour options is offered throughout the day. Tours focus on various cultural, culinary, historical and commercial facets off the city. A minimum 2-hour layover is required.
Also the transportation center at ICN has a free skating rink and a cinema showing first run movies. As with the transit tours, getting to the rink or cinema requires clearing immigration.
Final Thoughts
ICN offers so many neat activities and services that it is hard to list them all. I recommend inquiring at an information desk to see what options might work for your layover.
On my next long layover at ICN, I would love to visit the observation deck and take the free tour to visit the Memorial Hall to the 1950 Incheon landing where MacArthur landed behind enemy lines and cut off the invading North Korean army. I have always wondered which of the many islands one sees on approach and departure is Womi Doh, a key objective for MacArthur’s troops.
