Westall is perhaps best known as the artist who accompanied Matthew Flinders on his circumnavigation of Australia in 1801-3. The stress of the voyage seemed to have affected his mental health and in late 1815 following earlier bouts of illness, Westall had an apparent breakdown, which his friend Joseph Farington recorded in his diary with concern. To recuperate, he spent several summers travelling in the Lake District where he became friends with the poets William Wordsworth and Robert Southey. During one of these visits, Wordsworth persuaded Westall to make an excursion to Craven in Yorkshire, where he himself had visited in 1799.
While travelling in the Dales, Westall made drawings of caves and other geological features. This book contains proof plates of the aquatints that he published in 1818. The dramatic images inspired Wordsworth to write three sonnets in praise of the book, which were printed by Westall in Blackwood's Magazine the following year.
Initially, Wordsworth was not happy that his sonnets had been published but he continued to write verses inspired by the British landscape and such poems quickly came to be counted among his most popular works.