Ockelbo is a locality and the seat of Ockelbo Municipality, Gävleborg County, Sweden with 2,724 inhabitants in 2010. The name Ockelbo, spelled De oklabo in 1314, contains an old marine name *Ukle, referring to modern-day Lake Bysjön. The name derives from the old Swedish word ukla, meaning 'swell, gain etc.', alluding to the rapid changes in the water level of the lake. The second part of the name, -bo, means district or region. Approximately 150 ancient monuments are registered, including several Stone Age settlements.
https://en.wikipedia.org/wiki/Ockelbo