One of the entrances to a badger’s set. This one has at least half a dozen entrances: some setts can have many more.
A fox’s den is also excavated, but has a narrower hole.
CORRECTION – while this post was waiting to be scheduled, someone saw the inhabitants of the hole at dusk. They were a fox, a vixen and at least five very young cubs – perhaps four weeks old as their fur was starting to change to reddish brown.