Place is one of the foundational concepts on which the field of Geographical Sciences has been built. Traditionally, geographic information science research into place has been approached from a spatial perspective. While space is an integral feature of place, it represents only a single dimension (or a combination of three dimensions to be exact), in the complex, multidimensional concept that is place. With the increased availability of large, user-generated datasets, it has becoming increasingly apparent that the value of 'big data' lies not necessarily in its size, but in its heterogeneity. In my research, I exploit this heterogeneity to build computational, data-driven models of human behavior, taking a multi-dimensional approach to investigating place and the activities people carry out at those places. In this talk I introduce the concept of Semantic Signatures built from spatial, temporal and thematic dimensions extracted from user-contributed, and authoritative datasets. I show how these signatures can enhance existing geolocation methods, form the foundation of place-similarity models and contribute to visualizing the platial pulse of a city.