noun, verbal noun, の adjective
Let's go view some sunlight! Oh wait, we can't do that here. We will have to go sightseeing to go see this amazing sunlight thing.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
Do you have a sightseeing brochure?
It is difficult to get a hotel in Kyoto during the tourist season.
I prefer to go sightseeing on foot, but we rented a car this year because we have a small child.