Tower in Woolston

I've not been able to find out any details about this old abandoned derelict tower in Woolston. It's fascinating! It's very near the banks of the Heathcote River, so that may be a clue.

Today's Abstract Thursday's challenge is 'Travel'.
The steps going up the outside of the tower travel around the outside of the structure - I'm not sure that this is the correct interpretation of 'travel' for today, but it's what came to mind.