A marsh is a grassy meadow that is strongly influenced by salt from the sea. This type of nature is abundant in Denmark, among other places. The flatlands along the river that run out by Leirvågen, are the municipalities' largest marsh. At spring tide, these flatlands are flooded underwater for several hundred metres in over land.
Lake Purkebolsvatnet is perhaps western Norway's largest sleeping city - for birds. They come in the thousands, usually in later summer and autumn. The barn swallows alone number 10 000 - 12 000 at their most numerous.
Tthe Otterstad farms lie in the innermost part of Mofjorden, on the northwest side of the river. The row of stave-built boatsheds that belong to the farm were probably constructed a little after the middle of the 1800s. Both here and on the Mo side, the boatsheds were important storage places at the seashore; wood and other farm products intended for the town; corn and merchandise in return.
Furthest north in the island community Rongevær, at the entrance to Fensfjorden, lies Krossøy. Belonging to the farm are the islands of Krossøy, Husøy, Kårøy, Lyngkjerringa, Søre Kjerringa, Rotøy and Kuhovet. All of them have been inhabited. On Krossøy itself today there are four holdings. The marine use environment here is one of the best preserved along the West Norwegian coast.
If you take the sea route north you have several options. The various routes have been dealt with in history, and through the Middle Ages the traffic increased as well as the trading with Nordland in fish and herring, feather and down. One of the central routes passes through Kjelstraumen, in the sound between Ulvøy and Bakkøy. This has been a place for a guesthouse since 1610, with Royal Letter of Privilege, part of the large network of trading post and guesthouse locations along the coast.