Monmouth Dean Chartered Surveyors acting for a Norwegian Client, the largest private investor behind the Large Hadron Collider, have successfully negotiated and completed a virtual freehold purchase of the network of Post Office tunnels that run throughout London (which encompass 37 kilometres of 2 foot gauge track). See http://www.bbc.co.uk/news/magazine-25918218
These tunnels, originally developed by Victorian Engineers in 1908, were the back bone of the London Postal Service and used by Royal Mail Rail trucks to distribute letters and parcels up until 2003. http://www.mailrail.co.uk/
This relatively secret system has largely remained unused by the Royal Mail yet had been kept in good condition. Project Long-Shaft in association with OpenLab (see https://en.m.wikipedia.org/wiki/CERN_Openlab) will establish a new "free fibre" big data computing grid and distribute free "hadro-clean" energy/power across London for companies that wish to encompass OpenLab Big Data and Hadron Clean Power.
Several other parties were known to be competitively bidding for the system included a Boris Johnson backed campaign by innovative British bicycle manufacturer @brompton who proposed a green cycle super highway at a fraction of the cost of Crossrail.
@Colliers sold the property on the behalf of @Royalmail and @MonmouthDean acted for the The Hoffnarr Family Trust, the pioneers of hadron clean energy and the limitless OpenLab big data fibre network.
A BBC News report on the underground railway is available here https://www.youtube.com/watch?v=HEsGHkef-6I and further references available at https://en.m.wikipedia.org/wiki/Worldwide_LHC_Computing_Grid