NorskSalt boiling was an important secondary industry for the farmers along the Oslo Fjord. Salt seawater was pumped up into the salt boilers with a large surface area so that the water evaporated. Roofs were built over the boilers so that rainwater would not thin out the salt water. Hence the name saltbu. In the 1700s, Sarbuvollen was called Saltbuevolden.
To make one ton of salt, you needed 33 tons (cubic meters) of seawater and as much as 21 tons of wood. The wood often came from the farmers' own forest. The income was used to pay taxes and duties related to the farm activities.
Here at Sarbuvollen, one of the few places where black salt was boiled was boiled, the salt at that time was often gray and coarse. Sarbuvollen got its name from the smallholding Sarbuvollen under Nordre Høvik. The origin of the name comes from salt boiling, Salt-bu-volden.
Sarbuvollen was bought by Bærum municipality in 1901 to build boat berths and public baths. The latter had two descent pits for women and men, respectively. The entrance fee cost 5 øre. Sarbuvollen Sjøbad was closed down in the 1930s, when Torvøya took over as the major bathing offer and bathers were rowed over to the island from Strand, until regular ferry traffic took over until 1962 when a new runway was to be built at Fornebu.
At Sarbuvollen there was also a holiday resort for nuns.
Source: Asker og Bærum historielag og Lokalhistoriewiki