Lanipo (Mau'ume) is a beautiful ridge hike in the Kaimukī neighborhood of Honolulu.
Lanipo (Mau'ume) is one of my Honolulu hikes, mostly because of the amount of scrambling involved. I have yet to do the complete 7.5 mile round trip hike (if you want to see the rest of the trail I suggest you visit UnrealHawaii). We usually stop at a clearing about 1.5 miles in, and so far that has been enough.
This is a ridge hike, so you start at the top of Wilhelmina Rise in Kaimukī and climb down and up along the trail. Think manual roller-coaster. I have heard the phrase, "knife edge ridge" used to describe the width of the trail--and it fits. It is very narrow and rocky. Be careful, it can be hard to tell how much clearance you have on the sides because of the dense growth of ferns that cling to the mountain. This hike is harrowing on windy days, especially if you are not overly fond of heights; we have turned back on more than one occasion. Like I said, I love this trail for the scrambling. I have found that I really enjoy climbing down and up the rocky area at the beginning/end of the hike. It can be tiring, but it engages your entire body and makes for a great mental and physical workout. Although, that also means if you have issues with your knees or balance, I would say skip this trail.
One last caution: try to start early. For some reason we keep ending up on Lanipo at noon. I do not recommend it. Like most ridge trails, there is almost no shade and a nice breeze, which can fool you into thinking you are getting less sun than you actually are. Two words: sunburned thighs. We actually got stuck on the last 200 feet of rocks hiking back out to the mouth of the trail because we were dehydrated and exhausted. The day was hotter than we expected and ridge trails offer little to no shade.
Hike safe my friends!