You should find yourself in a small unremarkable, even unappealing dare I say, urban garden - but there is a story to tell here. The grassy areas here on either side of the road are the Highgate Enclosures and are remnants of from the middle ages when the area was all fields, much like the current Heath. Highgate Road was a muddy rural track with only the occasional coaching inn providing refuge from footpads and highwaymen.
This district was marked as 'Green Street' in John Rocque's map of 1746 as a part of the ancient settlement of Kentish Town. By the mid-19th Century they were much as they are now as green enclosures separating the villas of The Grove from Highgate Road on the eastern side and by 1906 overlooked by the Edwardian Lissenden Gardens Estate to west. In 1940 an air raid shelter was built in the most northerly enclosure for use by tenants of the estate.
But beneath your feet there is a more recent addition - Camden Council's nuclear bunker, known as Camden Borough Control and was ready to house vital post-apocalypse borough civic dignitaries.
The entrance is the concrete block on the west side of the lawns in front of Haddo House - the descending steps can still be seen through a small window. The shelter extends under the remains of the Highgate Enclosures and various escape hatches and ventilation pipes can still be seen popping up through the grass.
[Pictures from SubBrit]
These relics of the cold war are generally of no interest to anyone else using the Enclosures...
The magnetic nano cache location should not be much of a surprise. And as an additional point of interest, you are currently exactly 50m above sea level.
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