Mergelgrotten / limestome tunnels...

Today our second day of our five days trip to the Dutch southern province Limburg. After a relaxing breakfast & coffee-time we went to Maastricht, the capital of Limburg. We visited Fortress Sint Pieter, built in 1701-1702 to protect Maastricht & used by the Dutch army until 1867. After that we visited the tunnels under “Mount” Sint Pieter (basically it’s just a hill)  made by men when limestone was extracted. This is one of the many drawings made on the walls of the tunnels in the past centuries.