Part 1
During my walks around Hemel Hempstead I found this incredible tunnel located in Boxmoor, near the train station. It is painted with graffiti from bottom to the top - there is ~20 big pieces. The tunnel makes an amazing impression with graffiti painted up high to the ceiling.
Unfortunately tunnel is quite dark and several photos I took were not the greatest quality (well, it is a phone quality anyway).
I have no idea about who the artists/crews are, there was 2021 date on one of them, I will try to find out when I revisit the site to take better pictures of the missing ones.
Have a great day!