Johnathan Thurston (http://www.johnathanthurston.com.au/ ) told me today at Brisbane Airport (he was on the same flight out of Townsville) that he does Castle Hill in 11 mins!!! I did it yesterday but didn’t take much notice of my time (though I just checked and it looks like I took about 25mins to get to the top on runkeeper!!!). I was out exploring Townsville on foot starting at Castle Hill, returning to the Casino via The strand. Give it a go next time you are in Townsville, Awesome Workout & Magnificent View!!! –http://www.explore-townsville.com/castle-hill.html
I also spent two days on Magnetic Island prior doing two big trail runs to check out the beautiful scenery and the Forts walk which leads to historic WWII fortifications and infrastructure.
More info here, a must do if you are visiting the island!