So something new for me, drains. I am lucky to have several rather large examples in my home town of Bristol. Today we started with 'Dreadnaught' - a large storm drain built in the mid 70's to assist with a previous victorian drainage system on the south side of the river Avon. I won't bore you with the specfics, this one is quite a monster and most be 2 miles long.
Some more here:
http://www.whateversleft.co.uk/index...drain-bristol/