The trees on Kolokotroni Street, Kifissia, are full of colorful chewed gum. Urban myth has it that the first gum was placed here by children, but the idea caught on and the trees have been bursting with color for decades… Every so often, cleaners and gardeners alike have tried to clean the trees in this upmarket northern Greek suburb, but the gum immediately reappears.

The idea is not a Greek phenomenon. There’s a wall of gum at the Pike Place Market of Seattle. Theater workers scraped the gum away twice but gave up at around 1999. A scene for Love Happens featuring Jennifer Aniston was shot at the wall in 2008, and in 2009 it was named one of the top 5 germiest tourist attractions of the world.

Bubblegum Alley is a tourist attraction in downtown San Luis Obispo California. Colorful used bubblegum lines the 4.6m high and 21m long alleyway. Legend has it that the gum-sticking tradition started after WWII as a San Luis Obispo High School graduating class event, others say it was begun as rivalry between San Luis Obispo High School and California Polytechnic State University students.