If Batman had children

On a trip to the north of the country, you might come across the "Bat Tunnel" in Huldange, it's cold, dark and damp, a real horror movie set. You can go there with the kids, take a tour of the site and learn about bats, with sound stations and interactive multimedia terminals that have been installed on site. Unfortunately, you won't be able to enter the tunnel unless you have a good contact, as this tunnel is home to over 13 different species, some of which are super rare (you wouldn't want to disturb them though).