Rising early each morning, the young Charles Darwin and his brother Erasmus were led by their father Robert on a walk of silent contemplation around the grounds of their home in Shropshire.
The daily ritual lasted about half an hour and was designed to encourage the boys to reflect upon what they hoped to achieve with their day and how they would set about it.
The Thinking Path made such a great impression on the future author of On the Origin of Species that Darwin created his own Sandwalk route when he set up home in Kent with his wife Emma.
Charles Darwin's childhood garden in Shrewsbury is being opened to the public to celebrate his birthday.
Born on 12 February, 1809, he was raised at The Mount in a house built by his father.
The property was set in 7.8 acres (3.1 hectares) overlooking the town and the River Severn, and indulged the family's passion for nature and gardening.
One of Darwin's uncles on his mother's side went on to found the Horticultural Society of London, now the Royal Horticultural Society.
After his father's death in 1848, The Mount was sold and the estate was divided, with one of the largest shares now owned by Sharon and John Leach.
The Leaches own about two acres of the original walled garden including the woodland, riverbank and part of the Thinking Path.
Mrs Leach said: "My favourite spot is going down across the terrace, you go into the wood and there's such a feeling of calm.
"It's so still apart from the otters you hear rustling about and the sparrow hawks. There's a fox that lives down there and the chatter of birds too. It's so tranquil.
"There is a very large sweet chestnut tree at the rear end of the wood which seems to fit with a sketch we have seen of Charles and his sister Susan sitting in a sweet chestnut tree."
Using old maps and photographs, the Leaches have re-laid part of the Thinking Path.
"It's astounding to think of them taking their constitutional walk thinking about the consequences of their actions.
"When Darwin returned from his voyages on HMS Beagle, he spent a long time thinking about the items he had collected and what they meant. By this time he had created the Sandwalk at Downe House where he later published his theories of evolution.
"It's incredible to think that he was so profoundly influenced by the Thinking Path we have here."
South American fossils
Three years ago, Mrs Leach came across a "stinky, smelly, oily rag" in the garden near the ice house which she threw onto a bonfire. As she threw it, two fossils fell out of the cloth.
Preliminary investigations have established the fossils are giant pine cones of a variety found in South America.
The suspicion is they were among the collection Darwin brought back from his voyages in the Americas.
Cambridge University is carrying out further investigations and the Natural History Museum has also expressed an interest in the artefacts.
Harper Adams University College is organising guided tours of the garden on Sunday to mark 203 years since the birth of Charles Darwin.