Slickenside is a striated and polished face of a rock. Slickensided rocks are common in tectonically active areas because they are formed by frictional shear during movement of fault surfaces relative to each other.
The example above is from Cyprus. I stumbled upon it accidentally. It just lay there in the high grass waiting to be discovered. The chance to be discovered by a geologist is actually pretty good because the area surrounding the rock is extraordinarily rich in varied geology. There is an exposure of tectonic mélange, chloritized lava, exposure of trachyte with large sanidine phenocrysts, and pillow basalt within a rectange of a few hundred meters. Only few kilometers away are a hill made of serpentinite, a village (named Choletria) severely damaged by an earthquake, and bentonite which played a role in the destruction of the aforementioned village, and many more interesting rock types like chert, chalk, etc.
There are no signs directing to these interesting places. I am often astonished how little most people care about geology. Of course, this isn’t going to change. Rocks will remain boring for the majority of people in the future just as they are now but nevertheless I couldn’t stop thinking about how the place might look like for example 100 years from now. I think there is a good chance that it is a geopark with nature trails and lots of explaining info boards. There is lots and lots of potential for it in the region between Nea Choletria and Nata.