From the site introduction:
These pages pull together work on the concept of place from a wide range of disciplines. The term "place" does not necessarily have the same implications or meanings in the different disciplines. Furthermore, other terms are sometimes used in place of place, such as home, dwelling, milieu, territory, and of course, space. None of these, though, are necessarily equivalent to the notion of place.
The purpose of this set of resources is to try to cross-pollinate the notion of place across disciplines. Philosophy, for example (my own discipline), has much to learn from the way that other disciplines conceive of place, even as those disciplines have drawn on the resources of philosophy in order to reflect on place. There is no real attempt at a definition here, except perhaps by extension.