This unassuming office looking building on Finsbury Pavement, near Finsbury Square, is one of Equinix’s many London data centres. The small facility (6458 sq ft) is one of the most inconspicuous data centres I have found so far – it looks almost exactly like an office, however, this data sheet confirms it is a data centre. I rang Equinix and confirmed that the building is still operating as a data centre.
The building is shared with office space and has commercial units onto ground floor. According to this AJ article the building was designed by SKS Architects and constructed in the early 1980s.
There is some evidence of a data centre, with cooling units and communication antennas on the roof and on the building’s other facade there is a secure loading entrance. However, aesthetically this would be impossible to recognise as a date centre.