Over time these lakes gradually eroded their soft peat shores and spread (a process known as waterwolf). Some part of this area of water was later called the Vlie; it probably flowed into the sea through what is now the Vliestroom channel between the islands of Vlieland and Terschelling.
over time these lakes gradually eroded their soft peat shores and spread (a process known as waterwolf) some part of this area of water was later called the vlie; it probably flowed into the sea through what is now the vliestroom channel between the islands of vlieland and terschelling