Breath of the Wild
The Pico Pond is located just east of the Woodland Stable, right next to the Mirro Shaz Shrine. Within the water itself, Link will find some Hyrule Bass, Staminoka Bass, and some more rare Voltfin Trout. Some Pink Herons and Bright-Chested Ducks are also found in and around the water. Several enemy Water Octoroks can be found and will attack Link when he draws near.
Near the center of the pond, there is a Magnesis puzzle, where Link will need to place the block in its proper location to get a Korok Seed. A second Korok can be found at the southeast portion of the pond by jumping into the circle of lilypads.
Nearby Korok Seeds
Solve the block puzzle.
Dive into the circle of lilies.
Complete the rock pattern.