River Fossa discharges the Corpse River Lake.  Once a few men were fishing for char from a boat on the lake and then went to an islet, where the boat drifted away from them and they starved to death on the islet.  The river cascades down the valley over several waterfalls on its way to the Fossa Cove on the southern shores of the Berufiord Bay.  According to a legend, a kelpie lived in a pool below the last waterfall.  The people of the valley did all they could to get rid of it with no avail until baptismal water was poured into the pool.  During high tides, the estuary of the river became too deep for horses and the people travelling through had to make a long detour on narrow paths in the slopes above the last waterfall to continue if they did not want to get wet by swim-riding.  The old bridge still standing, which was built in 1954, improved communications considerably.

The Fossa Valley is framed with high mountains and during the darkest part of winter the sun does not shine there for 18 weeks.  It contained a whole parish of 18 farms in the past.  In the early 15^th century the plague killed everyone there, but in the 17^th century it was colonized again.  The ruins of the old farms in the valley are still obvious in many places.  In 1953 a broach dating back to the Age of Settlement was discovered in one of them.  The only inhabited farm in the valley nowadays is Eyjolfsstadir.

Many passers by stop by the estuary to search for semi-precious stones and rock Crystals.