Now is a good time to go feather hunting. That hammer is a nice reward. But it doesn't matter, you would just be helping yourself get the hammer next district since you can't get it now. It takes all 100 feathers from all districts to get the hammer. But you don't need it for the end of the game, it's just something to think about. I wouldn't, but full disclosure.
From the Rialto, go to Emilio's old place.
You are sent to the far east district to the border.
Talk to the injured guy on the roof.
Just go north to the red zone, and clear your way to the NE roof. Double kill a pair, then quickly get the archer. Directly under is where the guy is screaming, and four guards protect the door. Aerial kill two and then finish off whoever stays. Open the door after.
Kill the three, meaning assassinate the ones that don't target you and counter the one that does. Then just navigate the streets, not the rooftops, to take him to the other zone to the south. Kill a group in the streets, then two more at the end.
Pass through the door to complete.
Enter his ruined house for this mission.
Approach this building from its south side to climb up to the roof. Aerial kill two at once, then the last. Open the door to get allies.
Next group is further east. And the final is NW of there. Only notable thing of the final group is they have a pike enemy, so kill him first, or just open the cage, your call.
To the very SW corner of this district. Just climb its south face.
Six are now revealed. All are listed relative to the center of the district:
*NOTE: For the first one, if you really want to, you can wait to get it during the course of a mission up ahead. Up to you.*
South - Is just NE of #54. It's a huge bell tower, and you will have to do many leaping climbs no matter which side you go up, including at the top when you see the bells through the bars. Then just climb the N or S side of the steeple to reach the top of the cross. Jump SE to the hay cart.
Southeast - You can climb up it's south face, and leap climb near the top; can't get on from directly below the board.
East - This one is another tall bell tower, same as the 55th one, and it's over the jail your sprung that guy from.
This appears to the south of the 57th VP once you climb it. Just double-kill the front two guards and then anyone left.
Still three more VPs in this district.
North - If you check the map and you haven't gotten the last two VPs, you can enter the docks through an open gate on the western wall of the docks, probably still in the fog on your map. The VP is on the wall, so take the western roofs to reach the wall, then follow the path to the point.
Northwest - The VP is on the E Paolo, climbable up its west face.
Glyph 4 - Near the last VP, this is on the San Marco. Climb to its roof and look at the back of the front face. For the picture game, it's in the RPG, on the one guy's helmet, and then just look over the far end of the front line for something to appear in the smaller window on your scanner (not the line with the horses and I presume generals, the one behind them). And finally the monster on the upper right holds a flame with something in it.
West - Very near the border of the Ducale district. A more traditional bell tower climb.
27. Just near the SE travel station, it's on the side of the buildings facing the highlighted church.
28. From this little island surrounded by canals, you'll find the next feather above the bridge just to the west. More on a building.
29. Now go directly west to Bart's HQ and get this feather above his door.
30. From here, go NE to find this on a canal bridge.
31. From here you can see the next feather to the north, so go get it above the canal bridge near the dock entrance.
32.Go directly east to the canal along the SE edge outside the dock walls. The feather is over the street between the buildings, on the east side of the canal bridge.
33. Get inside the docks and head to the NW corner. This is on some boards between the buildings here.
34. Then get on the north wall and head east to find this feather.
35. Just southwest of the docks, outside the walls, on the north end of the building that looks west.
36. On the south side of a building right behind the Paolo (the east of the two highlighted churches in the NW of the district).
Back to Bart's house for this mission.
The first marker is far to the north, so just walk up the streets with your gang. Send them after the marked enemies, then kill the big guys first. Stand on the marker after.
Next marker is to the SE, mostly east. You can take out at least one with an aerial assassination if you do it fast.
Next pair are NE of here, and the only trouble is getting you guys there as I ran into two groups of enemies before the marker. The pair you must kill can easily be killed with a double kill from the air.
Back to Bart's to pick up the assassination mission.
This is a VP, and it requires a few leaps.
After you hit the marker to fire the signal, leap in Bart's direction to land in the canal, then go near him. Now kill two armored guards while they are aggroed and that's it.
Run north to fight in front of the docks. The big guy is the main target, Dante. You can't assassinate him, so just whip our your Altair's Blade (you bought it right?) and start fighting. No counter kills, just quick step and attack.
Now you must chase and kill both Dante and Silvio. You have like five minutes, but easy to do this in less than one. Follow them and their paths will be occupied with lines of guards. One key point is the first line, which they can break up themselves, and for some reason they pause, leaving a good spot to try for a double-kill. If not, just take them out one at a time. To get through the guard lines, just climb to any ledge and leap beyond them, even if you just leap along the wall. I imagine both are extremely easy to kill once you reach the ship.