Puzzle "Pentangle"

Difficulty: Extreme
Dimensions: 14 x 14 cm
Goal: Remove the ring

In this puzzle category, it's rare to find a solution by chance. You should count on a few days, or probably a couple weeks before "seeing" any solution. Your ability to solve it really depends on your level of experience and your perseverance.

A small hint: think of attacking this puzzle on each of its sides, it is an effective course of action...