Fondry des Chiens, also known as the 'Grand Canyon of Belgium', is a sinkhole in the Viroin-Hermeton Natural Park. It’s a protected and unique place in Belgium. The sinkhole is created by the seepage of rainwater through the limestone soil. These natural pits are called Fondries. You can enter the 20 meter deep Fondries and enjoy the beautiful fauna and flora. Besides visiting Fondy de Chiens, you can enjoy multiple hikes in this region.