The Jacobite Queen

I 'saw' this picture as I was driving over the newest of the swing bridges. So I parked in a humingous out of town car park which I then saw was fenced all round. So how do I get back to the swing bridge? Luckily someone else may have had the same problem and had put two of these big red plastic blocks they use at roadworks, as steps over the fence. Bingo! I was in. (Or out.)