Above ground at Green Park underground station, it’s hard not to notice the horizontal stripes of creamy stone built into the walls. At first glance, the thick bands of rock look like a cross section of old geology. Ascending the station’s steps feels like moving up through the layers of London’s bedrock. However, on closer inspection, it is clear that this material isn’t native to London at all. All over its face are thousands of impressions of small creatures that were once living deep under the sea.
The stone comes from the Isle of Portland in Dorset, which gives this rock its name. The swirls, spirals and shells are the fossils of creatures that lay on the seabed 150 million years ago. Over time, they were covered by calcium carbonate sediment, which, like the limescale in a kettle, formed on the bottom of the sea as it was heated by the sun. The sediment was condensed into limestone, leaving the shadows of the sea creatures calcified – literally – into the material.
“The blocky slabs of its design echoes the rough-hewn quarries on the Isle of Portland, which have helped to build London for almost 500 years”
At eye-level are larger impressions of the abstract shapes. These were carved by John Maine, the Portland artist who designed the shelter to be equal parts train station and sculpture. His architecture drew from the ancient prehistory of the material, as well as London’s obsession with it. After the Great Fire of London, Portland Stone became a fashionable choice for architects, who praised its resistance to erosion and its sound structure. The stone became visually synonymous with London’s grand architecture and can be found all over the capital: at Buckingham Palace, Whitehall, St Paul’s Cathedral, and on countless memorials. It has even been exported overseas: Portland Stone is what gives the United Nations headquarters in New York its distinctive off-white hue.
Green Park underground station, meanwhile, has managed to marry these two histories, one ancient and one recent. All the while, the blocky slabs of its design echoes the rough-hewn quarries on the Isle of Portland, which have helped to build London for almost 500 years.
This was published in the January 2017 edition of Geographical magazine.