The park names these two sites Kūkamāhuākea (Steam Vents) and Haʻakulamanu (Sulphur Banks), in Hawaiʻi Volcanoes National Park. At the steam vents, ground water seeps down to rocks heated by magma and comes back up as steam. At Haʻakulamanu, gases react to form pure sulfur, a yellow mineral Hawaiians call kūkaepele, and the underground heat leaves the area with very few trees. Visitors in the early nineteenth century gave it the name Sulphur Banks, in the British spelling. The Sulphur Banks Trail begins at the Steam Vents parking area, and the park rates it easy. The Sulphur Banks Bridge is damaged and closed, but the boardwalk and trail are open from the Steam Vents side. The gases at Haʻakulamanu are rich in carbon dioxide, sulfur dioxide and hydrogen sulfide, so people with heart or breathing conditions such as asthma, pregnant women, infants and young children should skip the Sulphur Banks walk. Cliffs, cracks and the vents themselves can collapse or be slippery, so stay away from their edges.
Start at the Steam Vents parking area; the Sulphur Banks Bridge is closed.