“Fractal art is a form of algorithmic art created by calculating fractal objects and representing the calculation results as still digital images, animations, and media. Fractal art developed from the mid-1980s onwards.” — https://en.wikipedia.org/wiki/Fractal_art
A series of pieces generated using fractal art software such as Chaotica, Apophysis and Flam3. If you want to learn more about fractal art, or even try it yourself, here are some links. You’ll need a relatively powerful computer, though, with a good graphics card, and even then it may take several hours to generate an image at high resolution. So be patient.