Sorry for making you think your life was over
Some people who deserve an apology: I caused them to believe they were about to die, quite badly. They weren't - and it was unintentional - but must have taken its mental toll.

I grew up in a medium to large town in the Chilterns - a town made entirely of glacial hills and valleys. One day some friends and I noticed that the weird grated outflow into the canal lined up perfectly with several large manholes placed along the route to our school. Much investigation - and recourse to the local reference library - showed that a river once existed along that axis but was no longer to be found.

It had been quite literally buried into a large underground pipe travelling nearly 3 miles across town and directly under our school. Subtle investigation found a few manholes that could be lifted and we used a car jack to widen the grille at the bottom end so we could get out, and began exploring an underground world using skateboards , torches and candles (the later in the chambers under manhole covers). We could travel several miles up and down the tunnel and go down some fairly tight off-cuts to rise up out of the ground in several places including, helpfully, in our own school grounds.

It was very useful as a way of quickly leaving grounds without using the gate or jumping the fence.

One day we were rolling along downhill when we realised beyond the usual gurgles of the water below and insane echoes off the concrete lining from our skateboard wheels, we could hear something ahead. People swearing and scurrying

It was a british waterways maintenance team. From their perspective, having entered through one of the more public manholes then tracked upstream for half a mile to inspect the tunnel (we assume) they thought they were alone. Then we pelted down the tunnel at them on rubber wheels, out of the darkness

They thought we were an oncoming flash flood and were crawling very fast but clearly aware they wouldnt have been able to get to the exit before we got to them.

Their reaction was a mix of shock, anger and relief. we reversed course, retreated up a side route too narrow for them to follow and lifted a manhole to get out. The next time we looked everything had been welded or bolted down.

So, to whoever you were, sorry for the near heart attacks.
(Carpe Cyprinidae, Thu 17 Jan 2013, 18:21, 2 replies)

I'm sorry
but there are no glacial landforms in the Chilterns
(rockdoctor, Fri 18 Jan 2013, 13:07, closed)

Yes there are. For evidence I refer you to the well documented glacial stone deposits around Kings Langley in Hertfordshire.. which is about the southernmost extent. Now be kind and shut up.
(Carpe Cyprinidae, Fri 18 Jan 2013, 18:43, closed)