burrow..

..of the garden wolf spider though this burrow is not in the garden but literally gnawed into the compacted sand and gravel of the morning bush walk.
The burrow can extend down as deep as 30cm!!

This spider spins a collar of silk around the entrance, the silk lines acting as trip lines sending vibrations to the waiting spider announcing that lunch is close by.
Some wolf spiders will build a 'door' that cover the burrow and others will roll a pebble across the burrow mouth to protect it from flooding.
All very enterprising.