Fish ladders are structures that Britons began building in the 19th century when they started damming and blocking waterways.
They can take a number of forms but all serve the common purpose of enabling anadromous fish (fish that travel upstream from the sea to spawn in fresh water) to bypass a man-made obstacle.
The fish ladder is the central metaphor in British writer Kate Norbury's intensely personal travel memoir, which recounts the number of explorations of rivers she undertook alongside the figurative journey in search of her own source.
Finding herself in a bad space after the stillbirth of her second child, Norbury needed a goal. She drew inspiration from a 19th century Scottish writer whose protagonist followed a river from the chilly North Sea to its frigid source in the Highlands, at a place named "the well at the end of the world". The image resonated and the theme for her summer became following rivers from sea to source.
Doubting she would ever make the same, actual journey that the fictional Peter Monroe made, she began exploring other, more convenient, rivers. One of her very early forays was to the Mersey, where we learn she had once been overwhelmed by the conviction that she had been born very near the spot she was standing on the beach. When she asked at a nearby convent whether it was possible she had been born there, the unsurprised sisters told her that it was quite likely. Indeed, they confirmed that this was her source - her birth and adoption both took place there.