The following page of the Spider-Man Miles Morales guide contains a description of the Memory Lane side mission which involves collecting all Postcards .
Rewards: 1500 XP
After completing the main storyline, return to Miles' home and go to bed. The next day Miles will get the first postcard from Rio with a clue where to find the next one. Therefore, they will not be immediately marked on the map like the rest of the collectibles. When you get to the marked location, a purple circle will appear on the minimap. Press R3 to listen to a hint regarding the exact location of the postcard. For every postcard you collect, you will get 5 tokens and 100 XP. Below, you will find a step-by-step description of how to find the remaining 7 postcards.
- Upper West Side - 1st postcard
- Midtown - 2nd postcard
- Greenwich - 3rd postcard
- Financial District - 4th postcard
- Chinatown - 5th postcard
- Upper East Side - 6th postcard
- Harlem - 7th postcard
Upper West Side - 1st postcard
The first postcard can be found in the Upper West Side. It is located near the leg of one of the statues which support a large sphere.
Midtown - 2nd postcard
The next postcard is in Midtown. Go to the observation deck at the top of the Empire State Building and find the broken binoculars. The postcard is on the ground.
Greenwich - 3rd postcard
In the museum in Greenwich, enter the terrace opposite the river. The postcard sits on a large shell.
Financial District - 4th postcard
The postcard from the financial district is on the speaker of the C.O.D.B.s Nightclub - jump on the lamp to reach it.
Chinatown - 5th postcard
In Chinatown, jump onto a giant lobster - the postcard is on its tail.
Upper East Side - 6th postcard
In the Upper East Side, the postcard is located at the gate in front of the El Barrio building.
Harlem - 7th postcard
The last postcard can be found in Harlem, on a basketball court, attached to a post.