Pre-Colombian fish weir, Panama
This is a photo of a pre-Colombian fish weir, or fish trap, taken on an island off the Pacific coast of Panama. At high tide, the weir fills with water and fish, then, when the tide recedes fish are left confined within the ring.
Now they are in a state of disrepair, but still clearly visible.
They were probably used in conjunction with the Barbasco plant, or a similar fish poison.