Here's a file I found a while back. Not Mars related, but pretty amazing. The national file is a delimited txt file with just about every geographical point of interest in the U.S. I've imported it into a SQL database and now run queries against it when I'm looking for a weekend road trip.

http://geonames.usgs.gov/domestic/download_data.htm

Would there be a way to query wikipedia for the same type of information, or combine the two sources?

I can't think of a way to query wikipedia - not like this allows. Once this file has been imported into sql (I use SQL Server), I run queries like SELECT DISTINCT [feature_type] FROM dbo.nationalFile WHERE [state] = 'California'

This will give me a list of all types of features in California. From there, I'll see something that looks interesting (like "lava field" or "mine") and I'll run another query like SELECT [feature_name], [latitude], [longitude] FROM dbo.nationalFile WHERE [state] = 'California' AND feature_type='lava field'.

This will give me a very clear list list. I can't imagine there would be a way to do this with Wikipedia, or any other online source that doesn't offer an API.

https://www.wikidata.org/wiki/Wikidata:Main_Page

If you dig, I think you can find RDF dumps of the database.