This ijskelder (in English, an ice cellar) can be seen at the Duin en Kruidberg part of the Zuid Kennemerland National Park in North Holland, one of several Ijskelders to be found there. In the 18th and 19th centuries before electricity and refrigeration, they were used by wealthy estate owners to store ice, so food and drink could be kept cool, especially in the summer. This one is set into a small hill (sand dune) with thick walls and is 8m deep, starting with a small corridor which widens into a pit. In winter ice was cut from the frozen ponds and kept inside the ijskelder, between bales of straw and leaves, this gave excellent insulation and the ice could be kept up to two years.
Since the 1990ís all the ijskelders in Holland have been modified and are now used as a winter refuge for bats.
Itís a bit dark to see in the photo, but there is a slit at the top of the door for the bats can gain entrance. Other bat sanctuaries in our area are old World War 2 bunkers left from the German occupation.