AllTrails has the largest collection of detailed, hand-curated trail maps with more than 50.000 trails so far. Wherever you might be, you can quickly find the perfect hike, bike ride, or trail run by length, rating, and difficulty level. The first time I used this free application (pro version with more functions is also available) was on O´ahu, Hawaii. Most of the trails are really well described, the references are honest – much better than the ones on Tripadvisor – and you can even follow the trails with your GPS.
If you want to enter the famous and illegal Stairway to Heaven on O´ahu on a legal way, I can recommend you to look for the Moanalua Valley Trail ( Article is coming soon 🙂 )
So what are you waiting for – go hiking!