Common Terns nesting at London City Airport - London - 26.5.2015

I am not sure whether they are nesting or not. There are a number of concrete platforms around the edge of the former dock, separated from the walkways by ten or fifteen feet of water. This old hawser seems to be fixed to one of them. Although people do go down to that part of the water to plane spot, it is not a busy area, so they could be using the recess in the rope as a nesting site.