Celebrate Earth Day at the Waikīkī Aquarium’s 18th Annual Mauka to Makai Environmental Expo on Saturday, April 12, 2025, from 9 a.m. to 2 p.m. This FREE, family-friendly event, presented by the City and County of Honolulu’s Department of Facility Maintenance, the Hawaiʻi State Department of Health Clean Water Branch, and the Waikīkī Aquarium, promotes the importance of keeping Hawai‘i clean and free of pollution, from the mountaintops to the ocean.
 
Guests will enjoy live entertainment, a native plant giveaway (limited to one per household, while supplies last), and interactive activities from various organizations including hands-on learning, arts and crafts, and educational exhibits that showcase ways to protect and preserve Hawaiʻi’s environment. 
 
The event is free and open to the public. Free parking will be available in the back parking lot at Jefferson Elementary School beginning at 7:30 a.m., with a free shuttle to and from the Waikīkī Aquarium courtesy of Waikiki Trolley. Guests are also encouraged to bring refillable water bottles to stay hydrated with our water stations.