Diageo has opened its Open Gate micro brewery in the centre of the capital, while a new book examines the vast complex that stands as one of London’s overlooked treasures.

Paul Knox’s Lost London from Yale University Press showcases the city through 25 disappeared buildings with illustrations.

The Guinness brewery that functioned for 70 years at Park Royal takes centre stage in this volume.

The site was erected in the 1930s when the company was shipping two-thirds of its porter from St James’s Gate in Dublin to Britain.

The former Guinness brewery at Park Royal once included rail sidings where trains in the company’s signature dark livery operated.

To cut costs, they set up operations on a 134-acre undeveloped site in northwest London, reachable by rail, the Grand Union Canal, and key roads.

The brewery operated its own rail sidings and initially used diesel locomotives before switching to ex-British Rail shunters finished in black Guinness colours.

Alexander Gibb and Sir Giles Gilbert Scott created the design blending contemporary industrial and Art Deco styles, with brewing beginning in 1936. The machinery derived from their Dublin brewhouse installed in 1879.

The 100-foot malthouse, brewhouse, and warehouses linked by elevated passages became a recognisable element of west London’s skyline.

Before the London site opened in 1936, two-thirds of the porter produced in Dublin was being shipped to Britain.

Although built to produce 650,000 barrels yearly, during the Second World War when supplies and transport from Ireland were disrupted, the location ramped up output of Guinness Extra Stout for southern England, eventually peaking at two million barrels annually.

Britain’s largest brewery operated under a paternalistic Garden Factory ethos. The 1,500 workforce enjoyed access to gardens, a working farm, allotment plots, sports fields, a bowling green, tennis courts, waitress-served dining rooms, and a public house called The Toucan Arms.

Staff could join sports clubs, secure mortgages for purchasing homes, and received three bottles of beer each day. Roger Bannister sometimes used the track for training ahead of his historic four-minute mile.

As drinking habits and technology advanced, Guinness diversified into other products, including producing Harp lager.

By 1997, Guinness had joined with Diageo, which positioned its headquarters at Park Royal but ceased brewing there in 2005, returning porter production to Dublin.

Despite drawing comparisons to Gilbert Scott’s Battersea and Bankside power stations, the brewery complex received no heritage protection and was demolished in 2006, an action Knox notes was condemned by the Twentieth Century Society as pure architectural vandalism.

He characterises Park Royal at the time of the brewery’s opening as the Silicon Valley of its day, home to leading firms including Heinz, Wall’s, Lyons, and McVities.

However, on its final day of operation in 2005, a commemorative bottle was produced, with the names of all remaining staff at the site fitting on its reverse.