Entrance is from the middle of the bridges
From the waypoint, an easy stroll with not much in the way of terrain, a 1lt yoghurt tub with lots of SWAG to trade with. BYOP.
Nice area to have a break and a picnic. bring your togs and you could even swim in the river, or at least a paddle.
Careful of the roads as heavy vehicles venture through this way a lot. And I believe it's placed higher than water levels when the weather is severe, but use common sense please if the weather has been bad.
And now that I've learned the hard way how high the water level really gets, I've update the cache location and given it rough new co-ordinates and the hint still applies.
Happy hunting!