Of course it is only the most ancient until an earlier one is found, but it is still interesting to hear that an artefact in England can make this kind of claim. I would have expected that there were more ancient structures in Mesopotamia or that region.
The Sweet Track is named after its discoverer, Ray Sweet who found it while digging peat in 1970. It was built across the marshy Somerset Levels to make it easier to travel between settlements. It has also been dated with surprising precision to one of two years, namely 3807 or 3806 BCE (presumably therefore by dendrochronology, although that is not clear). 200 tonnes of timber went into its 2000m length and it was probably prefabricated.