A view of the massive lock gate at the southern end of the Gloucester & Sharpness Canal where it empties into the River Severn. The Severn has the second highest tidal range of any river in the world, and from where I took this photo I was on a level with the canal (behind the gates) but you can quite clearly see the drop to the river. At a low tide as we had yesterday afternoon, there is around 48 feet (14.5m) between the river-bed and the water level in the canal

Check out the other Pbasers in this month's Challenge here