I'm planning on traveling with my company around Europe and I'm curious to know what cities in Europe would be the best place to go with a good forefront on PHP development.
For instance, Vancouver in BC Canada has a substantial amount of conferences and schools that support the language and a lot of people looking for work. I'd like to find cities in Europe that are just as prominent. Ideally I'd like to travel to four different countries and try to find some developers to work with.