One of the most charismatic and endangered species in Hawai‘i is the Hawaiian monk seal (Monachus schauinslandi). Only one in five newborn pups survives to reproductive maturity, and the species may be on the verge of extinction. For it to survive, the National Marine Fisheries Service (NMFS) knew that immediate and aggressive intervention was needed to enhance its recovery. The Marine Mammal Center – a non-profit agency that specializes in rehabilitation and care of wild marine mammals – worked with information and advice provided by NMFS to design Ke Kai Ola, a facility for the rehabilitation of injured or sick Hawaiian monk seals. It is located on a shoreline property under the control of the Natural Energy Laboratory of Hawai‘i Authority, at Keahole Point on the Island of Hawai‘i. The project has two in-ground, custom-built fiberglass pools and two smaller in-ground pools designed specifically for monk seals. The pools are surrounded by concrete haul-outs, work areas, and walkways, and the whole area is covered with a 60 by 120-foot shade structure. The pools are supplied with both warm and cold NELHA-supplied seawater so that temperature can be precisely regulated. The system runs as a flow-through system, bringing clean seawater in periodically for the health of the seals. Pool water is put through an engineered water treatment/life support system in which solids are separated, stored in a tank and periodically transferred offsite for disposal, and treated seawater is either recirculated to the pools or put into a discharge basin for environmentally safe disposal. A team of experts relies on the Center’s many years of experience in marine mammal medicine and health to treat monk seals so they can be released back to the wild. Geometrician worked with the Marine Mammal Center to ensure that environmental impacts were minimized and the public was informed. Ke Kai Ola has grown into a treasured part of Hawai‘i’s conservation infrastructure, the only hospital dedicated to Hawaiian monk seals.