Secrets of London are part of the collectibles in Assassin's Creed Syndicate. To Find them you need to solve series of riddles from the findings Reuge’s Vault in the city. Once you collect all the secret locations you'll unlock the Aegis Outfit for Evie. Here we have all the Secrets of London Locations in Assassin's Creed Syndicate.
These secrets are nothing but music boxes which you must pick up and there are 32 Secrets of London in the game. You need to hunt for them and once you've collected all bring them back to the vault to unlocks the Godlike trophy / achievement and the Aegis Outfit for Evie.
There are two ways to hunt for these secret music boxes, either you use your eagle vision and hear them when close enough or there is a map available at the E-Store which will cost you Real money. So to save you money and effort here we have all the locations for Secrets in London.
As we mentioned above there are about 32 Secrets in London, they can be sorted according to the locations: Whitechapel(4), City of London(4), Thames(4), Southwark(4), The Strand(4), Westminster(4), Buckingham, Westminster(3) and Reuge's Vault.
This Box is obtained during the cutscene when Entering the Reuge's Vault.
So Once you have collected them all, return back to the vault and insert all 32 discs and pull out the music box and it will start revealing the piece of Aegis.
There is also another way to see the exact location.