mentions the Rocking Stones and illustrates the Anvil and Porpoise Head. In 1906 the writer Harry Speight mentions the Elephant Rock, the Porpoise Head, the Dancing Bear, the Boat Rock, the Idol and the Rocking Stones. The identity of the Porpoise Head rock has been forgotten, although it appears in a drawing by Walbran. The mention of Druids appears in Brimham Rocks, the wonder of Nidderdale () by journalist Herbert W. Ogle (1871–1940) of Otley. He lists Druid's Head, Druid's Writing desk, Druid's Castle, Druid's Pulpit, Druid's Parlour, Druid's Kitchen, Druid's Coffin, Druid's telescope "and so on." The Parlour and Kitchen no longer exist. At the far end of the Eye of the Needle were once the Druid's Caves, which included a Parlour and Bedroom, but they have been exposed or obliterated by a rock fall. Other rock names mentioned in 1920 are Oyster Shell, Rocking Stones, Baboon Rock, Mushroom Rock, Wishing Rock, Yoke of Oxen, Boat Rock (also known as the Druid's Altar), Boat Rocking Stone ("first discovered to be movable in 1786"), Dancing Bear, Rhinoceros Head, Anvil Rock, Pivot Rock, Lovers' Leap, Frog and Tortoise, Cannon Rocks, Split Rock, Sphinx Rock, Rabbit Rock, Elephant's Head, Dog Rock (possibly the Watchdog) and Tiger's Head. In his Guide to Brimham Rocks published in 1863, local historian William Grainge wrote "These names are frequently changed by the innovating, garrulous guide, who has changed the Baboon's Head to the Gorilla's, and the Yoke of Oxen to the Bulls of Babylon, which unsettling of nomenclature he calls keeping pace with the times. Unique as the rocks are amongst the freaks of nature, there is nearly as much originality about the guide but infinitely less grandeur." In 2020 the National Trust produced Spot the Rocks, a discovery trail sheet for children, listing eleven of the rock names. Some recent rock names in use are Meerkat and Smartie Tube. Biological site content Peat was once dug on Brimham Moor. Heather-burning, grazing, management for shooting, and air pollution from industrialisation plus two hundred years of footfall from visitors, has limited biodiversity especially around the rocky outcrop. Some of the heath has not been affected. Flora At the east side of the Brimham Rocks site cowberry grows, it is "a northern species found mostly in Yorkshire." On the dry heathland by the rocks, on shallow soil with sand, grows a scattering of oak, rowan and silver birch,