The east coast is usually too rough to swim in, but here at Lydgate, they built a protected swimming area with lots of huge boulder to hold out the ocean. It's great for families and beginning snorkellers since the pond is usually smooth. Snorkeling isn't bad there, either! Fish get trapped in there during high surf. THe water did seem a bit murkier there than on the south shores, but it still wasn't bad for a quick place to go to snorkel on the East side.
There is also a great playground and picnic area for families to enjoy.
Being in Kapaa, it's also close to several resorts, restaurants, and shops. Including a big Safeway grocery.
The coconut grove here once served as a place of refuge for the ancient Hawaiians. Those who could reach the boundaries of the refuge before being caught were spared punishment or even death for breaking a kapu (law). The Wailua River begins near the north end of the park.