Can you guess what that is? It´s art of nature!

A samll cut tree branch with rings of concrescence. The circle was just about 5 cm in diameter.

Sandentnahmestelle Neustadtgödens, Germany February 2021

Canon EOS 90D |  Canon 100 mm  f/2.8 L |  1/60 |  f 32  |  ISO 400 | ~5 images overlay average mode