Caudebec is the capital of the Caux (named after Celtic tribe - the Caletes) region and is naturally in the form of an amphitheatre facing the Seine. A charter was granted in 11th century to the monks of St Wandrille Abbey and, a century later, the town was surrounded by fortifications to keep out the English. They failed.
On the way in from Le Harve direction is a museum about the Seine (again only open in afternoons but from March until October). Caudebec was one of
the towns which stood for the Huguenots during the Wars of Religion.
After the Edict of Nantes granted freedom of religion in 1592, the town became a prosperous glove and hat making centre. Alas, the Catholic Church didn't like this idea of Protestants earning all this lovely wealth, so they had the edict revoked, ending the period of prosperity in 1685.
Along the Quai Guilbaud there are abundant places to eat a picnic lunch. If you need to buy vittles, there is an abundantly-stocked supermarket off to the left up a side road beside the church, a flamboyant edifice built between 1425 and 1539 and described by Henri IV as "the most beautiful chapel in the kingdom". There has been a market in the square since 1390 (currently on Saturdays).
At the east end of Caudebec, observe the seaplane cut into the stone on your left near the 1280m long Pont de Brotonne which was built in 1977. The monument commemorates "Those of the Latham 47" who were lost in a bid to reach the North Pole in 1928. Roald Amundsen was among the crew of six who flew off from the Seine here at Caudebec to Bergen and Tromso and then simply... disappeared. They are probably sharing that semi in Romford with Messrs Maxwell and Presley.