1. A method performed by a data processing apparatus, the method comprising: determining excess queries over multiple time periods for two or more given geographic features, where each geographic feature defines a location; comparing the two or more geographic features for similarity based at least in part on the determined excess queries associated with each geographic feature; for a given target geographic feature, determining one or more similar geographic features based on the comparing; and relating electronically the target geographic feature and the one or more similar geographic features as a set of similar geographic features, wherein determining the excess queries over the multiple time periods for the two or more given geographic features includes: generating a geo-query count that represents a total number of times that the search query was received over a specified period; obtaining a corresponding expected query count for the at least one of the search queries by accessing a search query log that includes data specifying search queries corresponding to a particular geographic feature; comparing the geo-query count to the corresponding expected query count for the at least one of the search queries, the corresponding expected query count being a baseline number of times that the query is expected to be received; and in response to determining that the geo-query count of the at least one of the search queries exceeds the corresponding expected query count by at least a threshold amount, classifying the at least one of the search queries as an excess query for the particular geographic feature.