First of all...welcome to NP!
imo, geo names are always a good choice. I like the "explore" keyword as well as it relates to what you're trying to promote. Many successful sites use "explore" too.
explore seoul - 1.8 Google hits
"explore seoul" - 1,930 Google hits...still not too bad
I believe the big $ lies in developing this name as it could fetch a hefty ROI. If you were to flip this name to a fellow domain or end-user, I think it would fetch $xx - low-to-mid $xxx.