Bohuslan is in South West Sweden, close to the border of Norway and about an hour and half drive North from Gothenburg. The name of the area is the name of the region, much like we might use Peak District, Lake District or Snowdonia in the UK.
Whilst Bohuslan might not have the size and scale of other destinations (it's mainly single pitch climbing), what is does have is impeccable granite. Forget the quality of granite in Yosemite, Squamish, Mello, etc, Bohuslan is better. The best granite and routes in Bohuslan easily match up to the best pitches I've climbed anywhere in the world.
The easiest area to compare it to in the UK would be The Peak District. Replace the Gritstone with granite, the crowds with a few Scandinavians and scattered cattle and you've got it. A very green landscape is dotted with small crags, which are in farmers' fields and on small hillsides with easily accessible approaches. However, Bohuslan certainly has a few quirkier locations, including granite crags which come straight out of sandy beaches right next to the sea. Pretty amazing!