Instruct: Classify a review into positive or negative sentiment.
Query: Excellent and thorough travel guide

This is definitely one of the best London travel guides available. There is only one reason why I did not give it five stars, that being the lack of detail on the maps. The maps in the Eyewitness London guide are much better (though that guide lacks the kind of detail that the Rough Guide offers in other parts). The organization is outstanding, which is very important given London's enormous size. Other than the maps, everything else is absolutely outstanding.