On the eastern part of the island, near Hanauma Bay, is the Makapu’u Lighthouse and the trail leading to it. It’s an easy couple of hours in the sense that it’s a paved trail to the top, but that trail has a pretty significant and steady incline, so it could be difficult if you’re not used to the climb. The view is absolutely worth all the effort you’ll put forth, though!
From the top, you’ll be able to see (surprise!) the Makapu’u Lighthouse, and Eastern O’ahu’s deep blue ocean (not your typical green water). We often head to Makapu’u or nearby to watch for the humpbacks during the winter.
Also nearby is the Halona Blowhole, another gorgeous overlook along the highway, no hiking required. If you catch it on a good day, the Blowhole shoots air up into the sky. It’s also another great whale watching spot!
These are the only photos I have from the few times we’ve been over there, unfortunately. From the top, it’s about 1,000 times more beautiful looking out across the other side!