London is full of strange buildings. Sometimes it is difficult to work out what they were originally intended for.Here are some of my favourites. More details about Canonbury: http://tinyurl.com/pohsrgj
Watchman's shelter near Highbury & Islington station, London. In the days when the New River was an important source for clean water, a guard occupied this watch house to ensure that nobody swam or fished in the channel. He also had to keep a look out for people throwing dead dogs etc. into the stream or stealing the stopcocks and other fittings.