The first fragment is Kingston is hard to get because it is located on top on a chimney. The said chimney is on the roof of a building in the restricted area on the western side of the city. When you reach the chimney, you will notice that you can’t get the fragment using standard moves such as jumping. Therefore, you will need to jump higher.
To collect the fragment, you need to perform an air assassination on one of the soldiers around you. You can attempt it on the soldier that patrols around the chimney, or you can alert the guards on the ground, and then use the ladder to get back to the roof and on the chimney. When they approach, execute as many air assassinations as you can, until you get the collectible.