Labyrinths can be constructed from almost any material imaginable - brick, wood, turf, shells, etc. (I've even seen temporary labyrinths made from colorful scarves laid out on the ground...)
In the past year I have installed labyrinths using locally-sourced river rock to construct the walls and decomposed granite / sand to form the path. Below are photos and videos of some of those labyrinth installations . The labyrinth at our home near Springville, California is a replica of a Medieval period labyrinth that appeared in an 11th century manuscript of Boethius's "Consolation of Philosophy" from Abingdon Abbey near Oxford. It is a six-circuit labyrinth. The original manuscript version of the labyrinth includes a poem to the Virgin Mary inscribed along the path: "Assumpta est Maria ad Caelestia, Alleluia" (Mary is assumed into heaven, alleluia).
I also had the great fun (and challenge) of designing and installing a rock labyrinth at River Ridge Ranch / Institute located a few miles from our home. Gary Adest, the ranch owner, asked me to put one in as a permanent installation on the ranch, using ranch materials (rocks from the river beds), inaugurated on the opening of the first annual Foothills Festival in November of 2017. The River Ridge labyrinth (named The River's Edge Labyrinth) is a five-circuit Medieval era, processional labyrinth, with separate entrance and exit points. The labyrinth is approached from and exited via a couple of winding meanders that incorporate double spirals - a kind of ambulatory prologue and epilogue... For the Festival, labyrinth-walkers participated in completing the labyrinth by placing stones along pre-marked lines. I had put together about 97% of the labyrinth before-hand, and then together we worked to finish it before beginning the walk.
Below is a gallery of images and a brief video of the labyrinth from a birds-eye perspective. Enjoy! Both of these rock labyrinths are now registered on the Worldwide Labyrinth Locator.