Structured data-sets about geographical locations?

I'm new to looking for this sort of resource and am not having much luck so far. Basically, I have an interest in having programmatic access to a semantic dataset (would think most likely from a government resource) where I can get data on geographical locations (such as a specific beach, for example or a city). Most basic example is that for a city would have population info, etc..

Any resources for this to get me pointed in the right direction would be appreciated.