Mounds of detritus including plastic bottles filled with urine are polluting a historic entrance to the city.
The rubbish has been allowed to accumulate on the North Downs Way at Faulkners Lane, Harbledown, close to a lay-by on the A2.
Anti-litter campaigner Beverley Paton visited and photographed the scene.
She said: “‘This is an unbelievable assault to the senses. The smell and the sight that confronts you is a reeking cesspit in the the countryside, just a few hundred metres from a junior school.
“If you’re driving along the A2 into Canterbury, you can’t miss the continual trail of rubbish, but you will probably be blissfully unaware of the rubbish out of sight.
“Of course, if you have the misfortune of needing to stop in the lay-by to change a tyre, you will be just feet from bottles of urine and rotting food.”
Rubbish left at lay-bys has long been the source of a headache for authorities.
There have been calls in other parts of the district for lay-bys to be shut since they act as little more than parking areas for long-haul truckers and attract rubbish.
Drivers are known to urinate into bottles while they are on the road and then discard the bottles in undergrowth.
Sian Pettman, who organises community litter picks across Canterbury, said: “Any visitor entering Canterbury along the final two-mile stretch of the North Downs Way, the modern pilgrimage route to the city, will be welcomed by one of the most abominable eye-sores imaginable.
“Hundreds, if not thousands, of large plastic bottles full of urine carpet the woodland in a place where typically one might find wood anemones and bluebells at this time of year.
“The embankment between the A2 and the North Downs Way is a sea of amber bottles thrown out of their cabs by lorry drivers who have relieved themselves while on the move.
“Mingled amidst the sea of urine containers is a multitude of other items of discarded rubbish – brightly coloured plastic, polystyrene, take-away containers, vast quantities of cans and piles of unidentifiable waste.
“Walkers arriving in our city, people out enjoying the countryside, and those who need to stop at Canterbury’s lay-by deserve something better than this squalor.
“It seems ironic that pilgrims in the 21st century encounter a sight much worse on entering Canterbury than anything their medieval predecessors had to face.”
Canterbury City Council has been trying to encourage people to look after the district with its “Love Where We Live Campaign”.
It is also working on ways to reduce the use of plastic bottles which make up much of the litter found on streets and other open areas.