William Emerson was the son of a local schoolmaster. He began his working life as a mason and thatcher, teaching himself the rudiments of mathematics and mechanics in his spare time. Later, he lived in semi retirement and wrote influential books on maths, geometry, navigation and optics. His bedraggled appearance, prodigious knowledge and somewhat peculiar habits led locals to regard him with a mixture of fear and awe.

As he was a lover of ale, it seems appropriate that his birthplace is now the Emerson Arms. Nearby, above the entrance to the Bay Horse Inn, is a complex sundial, one of many fascinating timepieces the great man devised for the village. Emerson's altar tomb, together with the grave of his lifelong friend and pupil, John Hunter, stands in the churchyard of All Saints, at the heart of Hurworth. The church which was founded in the 12th century has a fine 15th century tower; although the rest of the building was restored and rebuilt in the Victorian Gothic style.

Emerson spent his adult life in apartments, overlooking the green. The house that currently occupies the site bears a plaque to this effect. The village green, surrounded by Beeches and Sycamores is an idyllic sight. Belying the fact that it is the burial site of the entire population of the medieval village which was wiped out by the bubonic plague.

The route leads over fertile farmland and crosses the River Tees into North Yorkshire at the red brick and sandstone Croft Bridge, which dates from the 15th century. A plaque records its restoration following the flood of 1753, in which the turnpike toll house was swept away. Beneath its seven arches lives a colony of Daubenton's bats; they feed on caddis fly and mayflies taken from just above the water's surface.

Nearby stands Croft Spa Hotel, built in 1835 to accommodate wealthy visitors who came here to take the waters. In 1714 a group of horses with swollen legs had bathed and drunk from springs underlying Spa Wood, and were supposedly miraculously cured. The waters were found to have some of the highest concentrations of sulphur, magnesia and iron in Britain.

A lane leads past Croft Hall, an impressive country pile that was once the home of Sir William Chaytor. Despite his beautiful house, he lived in distressed circumstances, and spent the last 20 years of his life as a debtor in Fleet Prison. Croft spa water was sent to him in prison to relieve his many ailments.

The fields are a dazzling sapphire blue on bright summer days when the flax flowers open their petals to the sunshine. Further on, the path leads into the shade of woodland and onto Monkend, where the Hall resembles a huge doll's house. Nearby is the former corn mill. The mill ran day and night until 1947 when the mill dam burst and the mill pond flooded into the River Tees; leaving the old mill motionless and mute. it is now a private residence.

Back along the lane in Croft-on-Tees is the old rectory, a rambling three storey house. In the 19th century, it had its own laundry, bakehouse and brewery, along with enough livestock to make its inhabitants almost self sufficient. In 1843 this became the home of the Reverend Charles Dodgson and his family of four boys and seven girls. The eldest Charles was later to find fame as the author, Lewis Carroll.

During his early youth in Croft, Dodgson was educated at home. His "reading lists" preserved in the family archives testify to a precocious intellect: at the age of seven, he was reading books such as The Pilgrim's Progress. He also spoke with a stammer – a condition shared by most of his siblings – that often inhibited his social life throughout his years. At the age of twelve he was sent to Richmond Grammar School (now part of Richmond School) in Richmond, North Yorkshire.

Close by is St Peter's, a long low church dating from the early 12th century. In the shadowy graveyard, weathered lichen encrusted tombstones lean at odd angles and Pippistrel bats weave darting patterns against sky at dusk.

Inside, the nave is dominated by the enormous 18th century two-storied family pew of the Milbankes. This was erected a pretentious six feet above the floor, a reflection of a time when the gentry flaunted their privileges in no uncertain terms. Lord Byron married a Milbanke and the newlyweds used the pew when attending services during their honeymoon at nearby Halnaby Hall in January, 1815.

Another feature of the church is a handsome monument of 1490 while a bronze memorial plaque is one of two mementos of Lewis Carroll to be found in the church.

More intriguing by the wall to the right of the altar is a 14th century triple sidilia that is richly carved with figures, flowers and a procession of animals. Down on the far right is a peculiar animals head with a leering expression that grows curiouser and curiouser as you walk away. The outlines fade and all that remains is the grin on the face of the Cheshire Cat.

The return route to Hurworth follows a track that passes the grounds of Hurworth Grange.