Slabs to build path on community garden, Reeves Corner! (Selhurst CR0)

Hi all - we're currently in the process of setting up a wildlife garden in the long-neglected and empty Reeves Corner!
We're in need of flat paving materials / slabs of any shape and size to create a more accessible pathway into the space.
We're looking to build this out of natural materials only.
DM if you're interested in getting involved too