An easy hike with gorgeous views. Go early to avoid the afternoon heat and crowd as parking tends to fill up quickly. If the tide is low you might be able to climb down to the tidepools from the top. The trek to the tidepools is a little more challenging since it is much steeper and the rocks are sharp. However, if you can it is highly recommended! One of Cassie's favorite hikes.
Another great trail. More challenging than Makapu'u Lighthouse but the views are stunning at the top. A great place to see the different microclimates of the island as it changes the higher you climb. Parking is in a residential neighborhood.
If you're heading to the North Shore, the Waimea Valley Botanical Garden is worth checking out. You can also see various cultural sites like a heiau (religious place of worship) and the kauhale (traditional Hawaiian living site).
In Hawai'i, there's a saying for food that tastes so good that it "broke da mouth". Waiahole Poi Factory is just that. This is real Hawaiian food. Don't forget to order their infamous dessert called, "Sweet Lady of Waiahole". Warm kulolo (steamed taro with coconut) topped with haupia (coconut) ice cream.