Although the entire island is a garden, Lawai Valley, near Po'ipu, harbors two unusual and expansive gardens--the 186-acre, private, non-profit Tropical Botanical and Horticultural Research Garden and the adjoining 100-acre, gracious Allerton Estate Gardens. Volunteer guides provide tours of both gardens by reservation. Also, managed by the National Tropical Botanical Garden is Limahuli Gardens on the north shore near Haena, which has one of the largest collections of native plants in Hawai'i and is truly a spectacular site.