“A map of the world that does not include Utopia is not worth even glancing at, for it leaves out the one country at which Humanity is always landing. And when Humanity lands there, it looks out, and seeing a better country, sets sail. Progress is the realisation of Utopias.” Oscar Wilde, from The Soul of Man Under Socialism.
Both a book and a website, “Utopia Britannica” is a directory of british historical communities from 1325 to 1945. As well as the community listings, there are stories about utopian settlements. There are many updates on the website which are not in the book.