Hoʻomaluhia means "to make a place of peace and tranquility." It is an appropriate name, though the garden's origin is less serene. After devastating floods tore through the Keapuka subdivision below, the US Army Corps of Engineers built a flood-control reservoir here in 1981. The gardens opened to the public the following year.

What resulted is one of Oʻahu's most quietly extraordinary places: 400 acres of botanical collections arranged by region, from the plants of India and Sri Lanka to those of tropical Africa and the Americas. The backdrop is the sheer green wall of the Koʻolau Range. The gates lock at four o'clock sharp, whether visitors are inside or not.

VoiceMap's self-guided audio tours use the garden as a finale, tracing Hawaiian plant knowledge, the Polynesian voyaging that connected these regions, and the traditional water management that the floods below so dramatically illustrated.