Unfortunately the vacation is now over. But I did come away with some nice photographs! We visited two Dutch cities – Arnhem and Maastricht. One of the places we visited in Maastricht was the caves of St. Pieter – the north caves to be exact. These caves were dug out to extract the limestone (or marl). At its largest it used to have 20,000 corridors and measured 230km. Now it measures about 80km.
Interestingly the first corridors were short enough that most adults would have to crouch to make their way through. As time went on and more limestone was needed, the floor itself was dug out, creating tall corridors that were easily 4-5 meters tall in some places. The guide also showed us ruts in the wall at some corners. The most efficient way to transport the limestone out was by cart and horse and horses tend to take the shortest way possible, which meant that they would push the wheels of the cart against the wall, creating the ruts.
The best part of the tour was when the tour guide asked us if we wanted to walk a bit of the caves in complete darkness. About 30 meters – this stretch had no turns on the left side for you to lose yourself, so all you had to do was keep your left hand on the wall and walk carefully/slowly. Note that this was an option – those who did not want to partake went on ahead with the lanterns and waited for us to arrive. It was incredible (and I humbly admit this was because it was in a controlled environment). I was nervous at a few points though!
Here are some photos of the drawings. Note that these were done in charcoal as that was the only medium that would not decay in this damp, cold environment (10c/50f year round).
This is a map of the caves (which is actually not completely accurate!), both the north caves where we were – look to the right where it says ‘ingang noord’ – and the other cave system. Note that there are only two official entrances nowadays, plus a 3rd emergency entrance/exit which connects the two cave systems. There used to be 17. Everything north of the red line already had all of the limestone removed that could be removed. Note also the black box on the right marked ‘kluis’ – that is where the Dutch placed 780 of their mot important paintings during the World War II to keep them safe, including Rembrandt’s Night watch. Climate controlled and everything.
You can also see on the map where we walked in darkness for 30 meters – near the noord ingang, above it and to the left, you can see a stretch of wall on the right side which has no turns. (We were walking it in the opposite direction, so we had to keep our hand on the left wall.)
Finally, in some places you can see huge empty spaces with the word ‘instorting’ – this is where the tunnels collapsed under the weight and pressure. (The tunnels are regularly checked for safety concerns, so I am sure they knew well in advance that it was coming down.) The latest estimates predict that the entire system will be collapsed and gone within 800 years.
So do not delay – visit today!