On the road between Hope Vale and Cooktown is a little sign on the right hand side that says "Isabella Falls" - 6km. You would miss this sign if you didn't know what you were looking for and more importantly you would miss the falls completely if you didn't know where they were!
The falls are not substantial by any stretch of the imagination but having said that I really loved them. You drive over a causeway and look to your left and you see what appears to be a waterhole or billabomg. It's not until you leave your car and walk the short distance towards the billabong and look back to the causeway, that you see the falls! They are remarkable!