You’ll find Calle Vechia running off Via Garibaldi in Castello. Those two white rectangles below the nizioleto (street sign) were notices in Italian and English a resident of that Calle had pinned there.
Here’s the English version. It’s striking how polite and restrained (usually) these communications are.
PS Bert sent me a link to information about the water tower he and Andrew discussed the other day. Have a look! http://www.m11watertower.org.uk/