The design is evocative of a sturdy padlock. Just pick it up and youll quickly gain an appreciation for the challenge that lies ahead - this puzzle will not open easily!

The interior is comprised of two elliptical pieces, locked together tightly around the circular pieces and obstinately refusing to be released. But dont give up! Repeatedly separate and then put them back together and prove you have what it takes to unlock this riddle.

• See at Puzzle Master