Castle Trail
(Punaluu)

Trailhead

Description: This trail is graded into a ridge spur along the west wall of Punaluu Valley, crosses the upper portion of Kaluanui Stream and Valley, and continues up upper Maakua Gulch until it reaches the Koolau Summit Trail. A spectacular trail, indeed, except it has borne the effects of many decades of inactivity and lack of maintenance. It was the second trail built in the early 1900s through the personal funding of a wealthy entrepreneur and landowner named Castle. The first Castle Trail (Olympus) was graded into unstable terrain along the Koolau crest high above Manoa Valley. It was highly susceptible to landslides and quickly fell into disrepair. What to Expect: The trail starts from the valley floor about halfway into Punaluu Valley. Once it completes its ascent of the valley's west wall, it crosses over the ridgeline (elev. 2,160-ft) and down into the next valley: Kaluanui Valley. When it reaches the bottom, which is still very high in elevation, the trail crosses a small, secluded, grassy campsite lined by rainforest. Immediately thereafter the trail meets Kaluanui Stream (elev. 1,960-ft). The trail continues beyond Kaluanui Stream up the opposite stream bank. It immediately follows several long switchbacks up the valley wall until you reach the ridgeline. At the top is of this ridge, which is Waiahilahila Ridge, is an unmistakeable "V"-shaped notch (elev. 2,360-ft). This is the end of the trail's first phase of construction. Shortly after the initial trail was built, a new phase of construction added a connector trail to the actual Koolau summit. This can be seen on the left side upon reaching the V-shaped notch. After passing through the notch, leaving Kaluanui Valley behind, the footpath turns left and heads mauka (toward the Koolau crest). It follows the graded trail etched into Waiahilahila Ridge high above Maakua Gulch. As you ascend, the two ridges - Waiahilahila Ridge (the one you're on) and Hauula Ridge (the one on your right) - slowly merge. At this merging, the trail makes a right-turn and contours perpendicularly from Waiahilahila Ridge until it reaches the Hauula Ridge. Once at the ridgeline, the trail again veers left/uphill and heads straight toward the Koolau crest. Beware: Mother Nature has long ago laid claim to this trail and has slowly been withering it away and populating the remnants with thick vegetation. Trailhead Location: The trail begins on the right side of Punaluu Valley Road as you drive into Punaluu Valley. The mapped distance from Kamehameha Hwy measures 1.5-mile (7,940 feet). The upper trailhead is a well-defined junction with the Koolau Summit Trail, about 65% of the way from the Kawailoa junction to the Poamoho junction. Accessing the Trail: There is no formal permission process to access this trail. The trail resides within a privately-owned valley - the trailhead begins on private property. Furthermore, the trail crosses Kaluanui Valley - the lower of which is home to the public Sacred Falls trail which has been closed indefinitely by the state (see why). No organized clubs have been known to have received permission to hike this trail during the last decade (or more). Property/Access: Closed/private property. Majority landowner: Bernice Pauahi Bishop Estate, multiple individual lessees Dangers/Other Considerations: While this trail is well-constructed, decades of neglect have caused this trail to become extremely overgrown and replete with slide-outs. As with all hiking, exercise caution and prudent judgement.