Fjøsanger is known among ice age researchers from around the world. Under an excavation in 1975-77, geologists from the University of Bergen found layers from the last interglacial, ca. 115 000 to 130 000 years old.
On the east side of Lake Skjelbreidvatnet, clearly visible along the road from Eikelandsosen, we notice a farm on a terrace above a grassy hill. The hill has the form of a broad shield; Skjelbreid (" Broad Shield") is the name of the farm.
Bays that are shallow far out into the sea, with fine sand and clay, are rare in Hordaland. Where they are found, the reason is usually that the edge of the glacier made smaller advances or stopovers when it calved back at the end of the last Ice Age. This is what happened at Vinnesleira.
The shift in the landscape is striking between the barren craggy moors north on Askøy and the green fields of Herdla, which has the county's biggest farm. The majority of Herdla, such as the island appears today, is a gift from the glacier: The glacier that advanced here over 12,000 years ago stopped at the northern tip of Askøy and took its time building up the moraine on Herdla. Since then, Herdla has been under continual transformation. The re-organisation of the loose sediment deposits continues today.
There is no place in Hordaland where there are so many over-wintering song swans as in Tjeldstømarka. And there are few places in the county that have had this birdfowl as a guest for as long.
Lysekloster was the largest agricultural property in the country when it was phased out during the Reformation in 1537. In its prime this cloister encompassed two-thirds of all the farms in Os. The monks introduced and cultivated new plant species and it was probably they who stocked the waters with fish not indigenous to the area. This legacy from the Middle Ages has left a lasting mark.