The Nakalele Blowhole Trail in Wailuku, Maui is an easy-to-moderate 0.3 mile to 0.7 mile out-and-back hike down to a rock formation nicknamed the "Blowhole". The Nakalele Blowhole is a geyser where seawater gets trapped in an underwater lava tube and shoots straight upward 100 feet into the air.
This GPS data only goes about half way to the blowhole since you can enjoy the sights from high on the ridge without having to hike down to the blowhole. For better views, plan to hike an additional 0.4 miles down and back along the rocky trail.
This is an extremely popular trail on Maui and most people end up hiking down and back in sandals and flip-flops; however, it's not easy hiking due to the terrain, so if you don't have hiking boots use sneakers.