More manholes with woodblock infills, hiding in plain view on London's main roads

This latest collection of manhole covers with remnants of wood blocks within them are specifically grouped together because they are all on streets I know well, so it's surprising it's taken me decades to notice them. 

First, here is a fabulous example in Holloway Road, ten minutes' walk from my home. I often lead guided tours here pointing out all the hints of late Victorian history when the street was often referred to as The Oxford Street of the North. Yet, although I often mention trams and old forms of transport, I hadn't actually spotted this fabulous example of wood blocks ...