This is a path in the garden of Belton House in Lincolnshire, England. If you can cross your eyes so that your right eye is looking at the left image and your left eye is looking at the right image then you will see a third image appear inbetween the two and it will be in 3D! It can be quite tricky to do but a good tip is to hold your finger up against the screen, focus on your finger and slowly move your finger towards you. You will notice that as you do this, behind your finger you will see a third image appearing inbetween the other two. Move your finger away and focus on the middle image!