It's a short hop from the bustle of Waikiki Beach—and right next to the always-buzzing Manoa Falls trailhead—but Lyon Arboretum is delightfully where the action isn't.
The botanical garden's 200 acres were planted a hundred years ago, and today offer a hike into an organized, fanciful jungle. The jagged green Ko'olau Mountains encircle the scene.
Don't walk too fast, since you will need a keen eye to pick up a fraction of the detail.
Lyon has been a research facility run by the University of Hawaii since 1953. To see the whole place requires nearly two miles of walking, with more than 200 feet of elevation gain.
On the other hand, you can lollygag around paths near the visitor center and gift shop, or find a bench and travel with your eyes alone. Oahu Trailblazer has more details on Lyon Arboretum and all the botanical gardens on Oahu. You could plan an entire vacation around visiting them.