How to stop snails from climbing up walls?

Does anyone know a way to deter snails from climbing up walls ?
We have heard of broken glass, egg shells and sea shells.

I have a wall approx. 1000m long so would need a lot of whatever to spread on the ground.

Hope someone can help - also places where I can purchase the stuff.

Many thanks

You can buy snail pellets from the local garden centres. Put them in the ground about a foot apart.
One good way is to set beer traps. Shallow tins put level with the ground and a bit of beer in each one will attract them and then they can't get out. Means you have to throw them away, though.
Sprinkle diluted ammonia along the bottom of the wall. The key here is "diluted", perhaps one cap full for every gallon of water or you'll damage the plants.

Copper tape, strips or mesh. Copper reacts with slug slime, causing an unpleasant disruption in the nervous system, apparently feeling much like an electric shock. The easiest material to use is self-adhesive copper tape – this can be applied across the threshold of a door and will last for years. Copper tape can also be wrapped around pots and planters

Or salt if you want to kill them but this can kill plants as well

Slug pellets are the worst thing to use if you have other pets. I had a cat die a very long painful death from eating some in a neighbours garden.

Hi Everyone

Thank you all, I'm going to get a mixture of everything today - we dont have pets so the pellets will be no problem.
Cheers
Kay