If you're looking for something very different to do in the city then this is a great choice, and not weather dependent. I did the two hour tour which takes you upto the emergency exit at the top of Crawhill Road. There has to be a second exit (Health & Safety) and you can see where you were by walking up there afterwards and finding the yellow "square manhole cover" on the side of the pavement. There are two histories to be told here. On the way up the Tunnel we learnt about the time when it was used as an air raid shelter during the 2nd World War, and what life was like here during that time. One person who had previously suffered from shell shock spent the whole of the war here. Blast walls were added to the original tunnel for protection during the war years. On the way back down the Tunnel we learnt about what led to the construction of the tunnel, how it was constructed, and some of the mishaps that beset the tunnel during its operation. The tunnel was cleverly designed to move coal from the mine on the town moor to the waiting ships on the Tyne using a gravity system of Wagon transport. Our two guides were excellent and very entertaining. Definately recommend this tour if you're looking for something different.