fen

A fen is a specific type of wetland that differs from a bog primarily through its water source. While bogs rely on rainwater, fens are fed by surface water or groundwater, making them more mineral-rich and supporting a wider variety of plant life.

In a geographical context, the term often evokes images of vast, flat, marshy landscapes, particularly in Northern Europe and the British Isles, where these areas have historically been drained for agriculture.