San Jose (California)
Headed to Oahu with the family and I'm interested in finding some nice hikes. We have my grandson and 8yr old with me so I wouldn't mind a couple nice family oriented hikes, but then my 18yr and wife would like to take some hikes that are a bit more aggressive.
Let me start by saying avoid Haiku Stairs aka Stairway to Heaven. Considering it is closed and illegal to hike. If you are lucky and you get caught you might get off with a warning when the neighbors call the police on you, if not face a possible fine or worse.
Here is a list of hikes on Oahu that are legal and usually well maintained: http://dlnr.hawaii.gov/dsp/hiking/oahu/#list
I would suggest keeping an eye on the weather on Oahu before you come and on the day that you do decide to hike. Because of the current weather conditions it has made some hikes very unsafe. So be prepared to do something else and if it doesn't look safe don't chance it.
PACK WATER AND INSECT REPELLENT AND DISPOSABLE PONCHO!!
I am so glad you are inquiring, and ready to "really" explore this beautiful island!
Due to the ages of those little ones; I recommend a place on the Windward side, just north from Kaneohe. It's a botanical garden called Senator Fong's Plantation and Gardens. It's quite large, over 700 acres! But beauty abounds and it offers so much information and history. They are open daily except Saturday, from 1000AM to 230PM. Less of a "hike", and feels more like walking through a lush tropical jungle. It should be more fun for those kids, and therefore for you with them!
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I have only done 2 hikes in Oahu, which were Koko Head & Diamond Head.
I'd say Diamond Head is still friendly for family. There were some stairs can be walked slowly step by step.
Koko Head was more steep.
But the view fom Koko Head was amazing as it can view Diamond Head and Honolulu, as well as Hanauma Bay.
Enjoy your hikes!