Given the expected high number of accessible digitally augmented devices and their communication requirements, this paper presents our work on creating a Web-based infrastructure for smart things to facilitate the integration, look-up, and interaction with such devices for human users and machines. To exploit the locality of interactions with and between smart things, the proposed infrastructure treats the location of a smart thing as its main property and is therefore structured hierarchically according to logical place identifiers. We discuss the infrastructure's look-up mechanism that leverages Web patterns to foster scalability and load balancing and features an advanced caching mechanism that greatly reduces the response time and number of exchanged messages. These properties are demonstrated in an evaluation in a simulated smart environment.