This is story related and cannot be missed. View Points are locations on the map that when synchronized open up other viewable areas of the city. Unsynchronized view points show up as a icon on the map. There are 66 total in the game scattered between the five cities on your map. They are mainly located in towers that you have to ascend, and not all are available to you when you first enter a particular city; more unlock as the story progresses. Some are more difficult to climb than others, and may require some ingenuity on how to reach the top. If it is not evident that you can climb one from the bottom, you may have to leap from a building to reach hand-hold points.
Once you finally reach the top, there is an eagle perch on one side (the eagle will fly away as you approach the perch). Stand on it and press to synchronize it. Repeat this 9 more times to unlock the achievement. You can unlock this as early as DNA Sequence 2.
There are 20 View Points available in Florence total but only 13 will be available to you through DNA Sequence 2 (the other 7 are locked in areas you won’t be able to access until DNA Sequence 4).