Again, stretching the Christmas theme a little, here are some lovely Swiss Alps (for that wintry feeling) and a promotional stamp celebrating the opening of the Gotthard Road Tunnel.
At the time it was the longest road tunnel in the world; now it has been relegated to fifth. It’s almost 17km long (just over 10 miles) and has one lane in either direction.
It wasn’t the first tunnel built under these particular mountains; rather the third. It sits alongside two rail tunnels – one built more recently (2016) and the original Gotthard Tunnel built way back in 1882 (see second link below if you like your feats of engineering to date back to the 19th century rather than the 20th).