Following the Red Road north you drive along the beautiful lava flow shoreline to the eastern tip of the Big Island. You eventually come across the Wai'opae Tide pools. That is if you can find them behind the all the homes built up in the area.
Note: These tide pools are no longer due to a lava flow that wiped them out.
These tide pools are different from what you normally see in other parts of the world. They are built into a lava flow that is slightly below sea level. Lava, having such irregular and layered structures makes for ideal areas to protect a wide variety of coral, colorful fish and other plants and animals.
Looking out you see a mix of snorkelers along with some long legged sea birds sharing the experience.
If you are short on time or without a snorkel, but have a waterproof camera, you can still get some amazing pictures since the water is so clear and you can walk out a ways between different pools.
This is a fitting way to end a short week in Hawaii, just scratching the surface of things to do and see.