The number puzzle on the beach in Big Walk shows a box with a MacGuffin trapped inside and a plank marked with two figures, 4166 and 1899. There is no switch to flip and no obvious mechanism, which is why so many players get stuck the moment they find it. The trick is that those two numbers are map coordinates, and you cannot act on them until you have unlocked the tool that reads them.
Quick answer: Finish the red tower to open the map room, take the paper map from the table inside, then send one player to the coordinates 4166, 1899 (south-central island, between the railway curve and the ski lift tunnel) to press a hidden button on the rocks while a second player waits at the beach box to grab the MacGuffin.
What you need before the puzzle can be solved
Leave the beach box alone at first. The coordinates are useless until you can read latitude and longitude, and the game only hands you that ability after the red tower is complete. Trying to brute-force the beach spot early is a dead end.
Complete the red tower by placing five MacGuffins in its console at the top. Doing so rewards a key that you shape at the cutters, which opens a locked room right next to the starting hub, sometimes called the gym or session spawn point.
Inside that room are two things. The floor holds a large 3D map of the whole island with every MacGuffin and landmark marked, but it has no coordinate grid. The table holds a foldable paper map with a compass, and that map does have latitude and longitude printed along its edges. Pick up the paper map before you head back out.
How to read 4166 and 1899 on the paper map
The map edges are labeled with two-digit numbers. To match them to the four-digit puzzle figures, treat each printed number as if it has “00” attached to the end. So the 41 gridline reads as 4100 and the 42 gridline reads as 4200.
With that in mind, the two figures point to a single spot on the grid.
| Figure | How to read it | Where it falls |
|---|---|---|
| 4166 | Between the 41 (4100) and 42 (4200) latitude lines | Roughly halfway between the two lines, since 66 sits near the middle |
| 1899 | Just under the 19 (1900) longitude line | Very close to the 19th longitude |
Where those two lines cross is your target. On the ground that lands in the south-central portion of the island, between the point where the railway curves and where the ski lift disappears into a tunnel, near the train tracks.
Press the hidden button and open the box
This puzzle needs at least two people because the button and the box are far apart. Split your group before anyone travels.
How to confirm it worked and why it can fail
You know the puzzle is done when the box on the beach opens and your teammate picks up the MacGuffin. That collectible counts toward the tower key it belongs to, so a successful grab is the only confirmation you need.
If nothing happens, the cause is almost always one of these.
- You went to the wrong crossing point. Re-check that 4166 sits mid-way between the 41 and 42 latitude lines and 1899 sits just below the 19 longitude line.
- Nobody is holding the button, or the button holder let go before the second player collected the MacGuffin. The box only stays open while the button is pressed.
- You are working solo. One player cannot hold the button and reach the beach box at the same time.
Once the MacGuffin is in hand, the beach puzzle is finished, and the train tracks beside the button give the traveling player a fast route back to rejoin the group.
