Karangahake Gorge is one of the North Island's most historic rock climbing areas, being developed mainly in the ’70s and early '80s. Access is pretty easy, there is a good variety of climbs of reasonable length and the swimming holes are superb. The jewel in the crown is China Wall with its long pitches on vertical rock. Most routes are mixed trad, with some bolts on many routes that otherwise require placed protection. In recent years local climbers have replaced many of the old fixed pitons, which protected many routes, with bolts, but the gorge retains its adventurous feel, even on fully bolted lines.
The Karangahake Gorge crag is in the north of the Kaimai Mamaku Conservation Park.
About 7 km from Paeroa, heading towards Waihi, you encounter a reserve on the right side of the road soon after passing under an old rail bridge. The reserve is marked as "Karangahake Gorge" (tourist attraction) on Google Maps.
At the Waihi end of the carpark area is a foot bridge. Cross the bridge. The Waitawheta river joins the Ohinemuri (the river that flows through the Karangahake Gorge) here. The main climbing area is up the Waitawheta but there is one crag further up the Ohinemuri – Black Wall – with 4 routes.
The usual access, the Waitawheta Track, on the true left of the river has been closed for more than a year due to slips. Locals still use it but it is not recommended during high winds or heavy rain. The Windows Walk is the open access. For this track cross the Waitawheta on the second swing bridge and immediately turn right up some stairs. Shortly a second set of stairs on the left brings you to a flat tram track. Turn right and follow this to the tunnels. Go through the tunnels (with some good view points of pipeline wall) and down wooden stairs. On the second platform before the bottom there is a steep rocky track on the left. This is the access track to the main walls.
If the tunnels of the windows walk is closed for some reason there is a high track that by passes it. 50m before the first tunnel the is a small track that weaves up to an old benched mining tram track. Follow this then the smaller track which will take you under Khan buttress. You will arrive at Prelude buttress and can drop down from there to the bottom of the shield.