Songlines does talk about using nature, including in the chapters by my Aboriginal co-author, Margo Neale, so from an indigenous perspective. The songlines are entirely linked to natural objects, from rocks and caves, to trees and mountains.
I talk a little bit about this in Memory Craft. In The Memory Code, I talked about about the reasons stones are particularly valuable in Neothlithic monuments such as Stonehenge and the thousands of stone circles in Western Europe/UK and in many other places in the world. Stare at stones and rocks and you will find that each one has an individual character. The bluestones which were transported to Stonehenge (the smaller ones, not the great big trilathons) are particularly blotchy, especially when wet. You can see endless images in them. A stone circle of bluestones, as Stonehenge was for 500 years before the big guys were brought in, would make an amazingly effective memory palace. But I even use a stone wall made of much smaller stones, as a palace. Each stone is so distinctive.
It works much better, though, if you move along a path in nature, as is the case for Australian Aboriginal songlines, Native American pilgrimage paths, Pacific Islander ceremonial roads, Inca cheques … they are all memory palaces in nature.
I use natural features a lot in my memory palaces. Every tree is absolutely distinctive, not only because of its shape and the images in the bark, but also for the context. I have one tree for the Chinese character for heart, for example, and I use the branches and trunk to map the character. It took a few moments imagination, but now when I look at that tree, the relevant branches stand out and make the character for me every time.
The fact that trees and rocks are so irregular is what makes them so good for memory locations - you can imagine anything into them - your brain will do it naturally, just as it does for clouds. The idea that they are non-distinct is not an issue, because plenty are distinct and these are the ones that you chose as a location. You don’t use every rock and tree, only the distinct ones.
Please try it. You will be surprised how perfectly it works. Also name each tree or rock or crevice or stream, path twist or natural step - and name something useful as indigenous cultures do. We tend to name things after dead people, but they will name it as ‘the rock with the red top’ - which I’d call Red Rocky for fun.
Just start at one point and find a distinctive rock, tree or start to a walking track. Then walk on a few metres (I usually do 10 - 20 metre distances) and look around for something distinctive for the second location. It works a treat!
I do hope that you tag me in any response if you do get a chance to try it.