The Tower Bridge is Significant to Sherlock Holmes because this is where the climax of the conflict and movie occur, including the spot of Sherlock and Blackwood's final showdown as well as Blackwood's final resting place. I found this summary of the scene and more information at Baker Street Wiki. This is an example of low barriers to entry because anyone with access to the internet is capable of loading up this Wikipedia and editing the page. Due to many people being able to access and edit this page, many authors have touched this information, shaping it in a variety of ways. Mapping this location on COVE makes visible a place a "gatekeeper" platform might otherwise bury because platforms with algorithms that actively shape meaning don't often promote computer generated scenes from a few minutes of movies.