They were well equipped this foggy day for a perfect adventure.  The Rheinfels Castle, with its extensive mine tunnels were beckoning.  The castle sits high above the Rhine, strategically placed just before the river turns wild.  This location encouraged many travelers to pull off and regroup before hitting rougher waters at which point tolls could be collected.  It was also a target for invaders.  Clever castle guardians devised an intricate system of tunnels which allowed them to plant land mines many yards away from the compound.  The mole like burrows are just about boy size, unlit, damp, and irrestible. You know we had to try this.