I was in Honolulu looking up a restaurant or something on Google maps and I saw a marker for "Manoa Falls". I had never been and I assumed it would be like Opaekaa Falls or Wailua Falls in Kauai. Both of those are just off the road. You get out of your car, walk 50 feet, see the waterfall, get back into your car. At worst I thought it might be like Akaka Falls on Hawaii which is nice paved with steps and walkways with rails.
Instead it was a dirt path about 1 mile long. It was a drizzly day and so it was all really muddy and slippery.
Monoa Falls is just a few minutes from Waikiki in Honolulu. Apparently some scenes from Lost and Jurassic Park where filmed here.
My first indication it might be more than I had expected was when I went to pay for parking they asked if I wanted to buy mosquito repellent. I didn't buy any and as far as I know I didn't get bitten but I probably should have got some just to be more at ease. That's also why I don't have better pictures. I felt like if I kept moving I could maybe avoid the bugs but if I stopped they'd get me instantly. I don't know if that's true or not but it did make me go as fast as possible.
I was only wearing sandals and I had a relatively nice but short sleeve shirt on. Hiking shoes and a t−shirt would have been more appropriate. In fact if there is a bug issue maybe long sleeves and jeans would be even better? It wasn't hot outside, probably around 72°F but by the time I got to the falls I was really pouring sweat and by the time I got back my sandals were covered in mud.
Still I'd highly recommend it. It's not often you get to trek through a rainforest.