| Angers, France | ||||||||
| Bergen, Norway | ||||||||
| Bern, Switzerland | ||||||||
| Budapest, Hungary | ||||||||
| Edinburgh, United Kingdom | ||||||||
| Florence, Italy | ||||||||
| Graz, Austria
George Town, Penang, |
||||||||
| Istanbul, Turkey | ||||||||
| Kraków, Poland | ||||||||
| L’viv, Ukraine | ||||||||
| Lyon, France
Luxembourg |
||||||||
| Moscow, Russian Federation | ||||||||
| Nancy, France | ||||||||
| Naples, Italy | ||||||||
| Paris, France | ||||||||
| Potsdam, Germany | ||||||||
| Prague, Czech Republic | ||||||||
| Riga, Latvia | ||||||||
| Rome, Italy | ||||||||
| Seaton, Jurassic Coast
Sintra, Portugal |
||||||||
| St. Petersburg, Russian Federation | ||||||||
| Stockholm, Sweden [Observer Member] | ||||||||
| Strasbourg, France | ||||||||
| Tallinn, Estonia | ||||||||
| Vienna, Austria | ||||||||
| Warsaw, Poland | ||||||||
| 28 | ||||||||