Cities are supposed to be built for all of us, but they aren't built by all of us. Every city in the world has been designed and built by men. But what if the other half had a go? Barcelona might be able to give us that answer. For the past four years the city has had a female mayor with a profoundly feminist agenda. We spoke to feminists working in urban planning in the city to find out what they think needs to change to make cities better for women.