Humber Fort - Bull Sand Fort

I've been wanting to have a look at this fortress in the Humber for a while - Bull Sand Fort, this is the one way out in the Humber and marks the southern point of the main shipping lanes. Bull Sand Fort is 1.5 miles from shore off Spurn Head. It is a 4-storey concrete building with 12-inch (300 mm) of armour on the seaward side, and originally armed with four 6-inch guns. Today was suitable for a blast down the river to visit this monument. 47 kilometres covered and I'm feeling it..