At Spjutøy and Straumsosen there are three entrances from Lurefjorden to the fjord basin inside. Right up the end of the 1800s the ferry could not reach further than to Mølna at Spjutøy. At Skallestraumen there was a bark mill driven by the powerful tidal current in the sound. Here was also a store, a bakery and a hostelry place around the middle of the 1800s.
Yddal is one of the biggest and finest pine forest areas in the county. The rich forest resources provided an important foundation for the settlement of Yddal. Up until about the 1950s, there were three farms here. Where the lumberjacks couldn't get to, the trees grew very big and can be over 300 years old.