This ride today is perhaps where they had intended to ride yesterday until they met a puncture victim.  The engineering works Charlie speaks of, and is much impressed by, are all part of the Liverpool Corporation water works built in Victorian times to collect water from the surrounding hills for piping to Liverpool.  The lakes Charlie refers to are actually reservoirs.  They form quite a large complex of five reservoirs and the area is a very popular place for cyclists and walkers to get off-road and away from traffic.  Hint, hint !