‘My husband saw a stalagmite sky as he went to water the plants on a hot and humid evening,’ said Melissa Deighton (Member 65,921). The cloud shadows appeared over Mickleover, Derbyshire, England as the Sun sank behind the silhouetted trees. Turreted Altocumulus clouds like these are known as Altocumulus castellanus. They were casting shadows up onto the Cirrocumulus cloud layer just above to appear like a cityscape of the sky. ‘I see a city,’ wrote the naturalist and essayist Henry David Thoreau in a journal entry in July 1851, ‘the eternal city of the west, the phantom city, in whose streets no traveller has trod, over whose pavements the horses of the sun have already hurried, some Salamanca of the imagination.’