Deep under the municipality of Tujetsch, a gigantic structure has been built over two decades: With a length of 57 kilometers, the Gotthard Base Tunnel as the heart of the NEAT (New Rail Link through the Alps) is one of the longest tunnel tubes in the world. As STEINer Sarnen Switzerland, we felt obliged - nomen est omen (Stein = stone) - to erect a monument to this monumental work in the stony Gotthard massif. On two tours, the NEAT Experience Trail in Sedrun provides interesting and sometimes surprising insights into the construction and operation of this century-old structure. Twelve stations - eight of which are also open in winter - encourage visitors to play and try things out. Interested visitors can follow in the footsteps of the two miners Matteo and Mauro. On the path, which is mostly wheelchair accessible and suitable for baby carriages, they learn more about tunnel construction and gain an impression of the hard day-to-day work underground. In addition, there are fascinating insights into the technology and planning and construction masterpieces of tunnel construction as well as information about the challenging geological composition of the Gotthard massif. In summer, there are also further highlights to discover in a playful way with the blasting pass, and a well-deserved reward awaits the young tunnel builders at the end.