Koko Crater Botanical Garden, Botanical garden in Koko Crater, Hawaii, US

Koko Crater Botanical Garden is a botanical garden set inside an extinct volcanic crater on the eastern tip of O'ahu, Hawaii. It is divided into distinct plant sections, each dedicated to species from a specific region such as Africa, the Americas, or the Pacific.

The garden was founded in 1958, and in 1966 it received the secondary name Charles M. Wills Cactus Garden in honor of an early supporter of its plant collections. Over the following decades, new sections were added as the range of plants grew beyond cacti to include species from across the Pacific and beyond.

The garden lies inside Koko Crater, a tuff cone whose Hawaiian name is Koko Head, not Ko'olaupoko; Ko'olaupoko is the name of the surrounding O'ahu district. The garden was established in 1958 and is still being developed, as its official site noted in 2013. Its dry crater floor holds collections grouped by region: Africa, the Americas, Hawaii and Pacifica.

A loop trail of about 2 miles (3 km) winds through the garden and takes roughly an hour and a half to walk at a comfortable pace. The ground is uneven in places, so sturdy shoes are a good choice before heading in.

The garden holds a native grove of wiliwili trees (Erythrina sandwicensis), one of the few such stands on O'ahu. The garden's roughly 500 trees represent about 200 species, and the wiliwili grove sits among plantings from Africa, the Americas, Hawaii and Pacifica.