Dublin Explorer - Glenasmole. Another one from the vaults. This time Isaac - then aged six - and I set off to explore Glenasmole/Bohernabreena, Probably the most extraordinary combination of natural wilderness and engineering to be found in the Dublin Area. The two reservoirs were built in the 19th century to provide clean drinking water to the Township of Rathmines, without interrupting water-power to the mills along the river Dodder - of which there were many. We meet some interesting characters and discover more than we had bargained for.