The area covers over 90 sq. km and includes two glacial tunnel valleys within Gniezno (Żnin) Lakeland.

  • Żnin (western) tunnel valley with the lakes Duże Żnińskie and Małe Żnińskie, Skarbińskie, Weneckie, Biskupińskie, Godawskie, Gąsawskie, and Oćwieckie; the valley has flat banks and is sparsely wooded; the western tunnel valley is also protected for cultural and historical reasons; Biskupin, Gąsawa, Wenecja and part of Żnin are within its borders;
  • Wójcińsko-Chomiąska (eastern) tunnel valley with the lakes Chomiąskie, Foluskie, Ostrowieckie, and Kierzkowskie; this valley has steeper and more wooded banks; due to the lie of the land, the landscape of the Wójcińsko-Chomiąska tunnel valley is very attractive, and many holiday centres have sprung up by the local lakes.