Lichen by the Itchen

This is lichen on a handrail on the footpath that runs along the Itchen Navigation. I like the way seems to go on forever.
The Itchen Navigation is a 10 disused canal system that provided an important trading route from Winchester to the sea at Southampton for about 150 years. Created by an Act of Parliament in 1665 progress was slow and the navigation was not declared complete until 1710. It was known as a navigation because it was essentially an improved river, with the main river channel being used for some sections, and cuts with locks used to bypass the difficult sections.