This 37-page book provides a description of five racial neighbourhoods for fantasy cities - one for each of the major races of dwarves, elves, gnomes, halflings, and half-orcs. Each community comes with a description of the local architecture, it's social atmosphere, descriptions of characters and businesses likely to be encountered there, what magic is likely to be in use, and a selection of plot hooks.
The dwarven and halfling communities are both fairly typical, the sort of thing that might be found in any generic, multi-ethnic fantasy city. Either could be taken out of the city, and used as the basis for a town inhabited by that race, and general guidelines for how they live. Thought has been given as to how underground communities will be structured, and there are some rules guidelines for moving around in halfling-sized buildings.
The half-orc community is also generic - at least assuming that half-orcs aren't a social elite in your campaign world, which seems unlikely - but is more tied to the rest of the city. Much of the description here would work just as well for any slum area that's more frequented by beggars than it is by the Thieves' Guild.
The other two, however, are more specific. The elven neighbourhood is a scholarly retirement community, and the gnomish one a Vegas/Blackpool-style gambling district. Both make perfect sense, but, in most game worlds, they're likely not the typical elven or gnomish quarter, merely one example of a specialised variant. That doesn't make them less useful, and the material on how, for example, high-class casinos might work in a fantasy world, could well be handy whether or not gnomes are involved. But it's worth bearing in mind.
The book is well written, and passably illustrated, and includes a lot of useful ideas and rules that could apply further afield than the dwarven equivalent of Chinatown or Little Italy.
[4 of 5 Stars!]