Lyon Arboretum, Honolulu

The Harold L. Lyon Arboretum, spanning 200 acres and overseen by the University of Hawai, is situated at the upper part of Mānoa Valley in Hawaii. This arboretum and botanical garden houses a predominantly man-made lowland tropical rainforest, complete with various trails and small water bodies.

Originally set up in 1918 by the Hawaiian Sugar Planters' Association, the Arboretum aimed to showcase watershed restoration techniques and evaluate different tree species for forest regrowth. It also served as a collection point for economically significant plants. Dr. Harold L. Lyon, a plant pathologist and botanist from Minnesota who worked with the HSPA, was its first director. He played a crucial role in planting about 2,000 tree species there. In 1953, following Lyon's recommendation, the HSPA transferred ownership to the University of Hawaii, with the condition that it remains an arboretum and botanical garden. The arboretum was renamed in honor of Dr. Lyon following his death in 1957.

Today, the Lyon Arboretum focuses on expanding its tropical plant collection, with a particular emphasis on native Hawaiian species like Pritchardia palms. It boasts over 15,000 plant entries, primarily featuring monocot families such as palms, gingers, heliconias, bromeliads, and aroids. The gardens display a variety of native and Polynesian cultivated and wild species, especially in its ethnobotanical, native ecosystems, and Hawaiian sections. The arboretum also operates an active seed bank.

Why You Should Visit:
The Arboretum is basically embedded into the Hawaiian mountainside landscape and it's HUGE – makes you feel like you are in an actual jungle.
The walking part is easy. No steep inclines; no slippery paths (unless you go there after a big rain); no narrow passages. Very pleasant and suitable for all ages.

Tip:
Make sure you have water as it gets humid and there's very little breeze. In Manoa, it rains quite often so bring a light jacket or a poncho if you plan to do the hike.
Try to take a tour because they are so informative, and then, try to reserve enough time to stay longer and continue exploring the extensive grounds on your own.
If you like to do conservation work, call the Arboretum in advance so you can join a group. Usually, it's on a Saturday.