Hellisøy lighthouse was lit for the first time in 1855. The characteristic red cast-iron tower with two white belts is 33m high and a light height of 46m above high tide.
Holmengrå is the only place in Hordaland where we find traces of the abrasion that is supposed to have transformed Western Norway from a Himalaya-like high mountain landscape during the earth's Paleozoic Era, to a flat lowlands terrain during the Mezosoic Era. Just 400 million years ago, large and small stones plummeted down from the high mountains. Some of these stones became incorporated into the conglomerate bedrock on Holmengrå.
Both Lure Fjord and Lindåsosane to the inside give good living conditions for rare marine organisms: jellyfish, shellfish and fish. These include animals that migrated in after last the Ice Age, when the sea level was higher. Eventually, as the land rose, some of these populations became isolated.
There is a lot of trout and a large char population in Lake Rylandsvatnet. The lake was stocked with char, probably in 1907. The promoters of the project were the family Ameln, who owned eight mills in Rylandsvågen and parts of the Ryland farm.
It is said that the salmon populations with the largest and the smallest salmon in the world both come from the waters that run out into the fjord system around Osterøy. Vosso is supposed to have the largest spawning salmon to be found in any river, whereas Lonelva is said to have the smallest.
In the late 1800s, Ekso was known among the nobility in England as having among the best salmon rivers. In summer the Lords could haul in big fish of up to 25 kg. In return, the townsfolk were paid for fishing rights, lodging and local assistance.