Roblox Game
Sell Lemons Sewer Map & Key Guide
Interactive sewer maze map with levers, doors, keys, and POIs — plus step-by-step Sewer Key and UFO Key routes and when to rejoin the server.
By Bloxron Editorial Team · Last updated
Drop into the sewer from any main-street manhole. Use the interactive maze map to filter levers, doors, keys, and other points of interest — then follow the step lists for the Sewer Key and UFO Key routes.
Important
Leaving the game resets sewer lever progress. Any keys you use stay used forever — finish what you started before you quit.
Fresh server between keys
Join a new server and follow one walkthrough at a time. Rejoin after completing each key so levers do not get stuck.
Interactive sewer maze
An unofficial map of the Sewers, which displays the general layout of the maze, including locations of Points of Interest.
Sell Lemons Sewer Maze Map
41 markers shown · click a pin for full details · visited pins stay highlighted
Hover a pin for a quick preview, or click to see lever requirements and door types.
Full map with key routes
Printable overview including Sewer Key and UFO Key step lists on the image.
Map legend
Lever
Red-and-white checkered cube. Flip ON or OFF to open and close colored doors.
Closed door (lever ON)
Solid colored bar — red, blue, green, or purple. The path is blocked.
Open door (lever OFF)
Jagged colored bar. The corridor is open while that lever stays off.
Cosmic Vine
Cash reward node behind a gate. Use the Sewer Key once to unlock the shortcut permanently.
Homeless Alien
NPC in the maze. Required for the UFO Key quest — speak before and after collecting the key.
Sewer Key
Green key icon on the map. Unlocks the gate blocking the Cosmic Vine.
UFO Key
Gray key icon. Requires rebirth. Completing the alien quest grants the Good Samaritan Badge (2× investor bonus).
Sewer Key
Blue ON → Red ON → Green ON → Red OFF → Blue OFF → Purple ON → Red ON
- Flip the Blue lever
- Flip the Red lever
- Flip the Green lever
- Unflip the Red lever
- Unflip the Blue lever
- Flip the Purple lever
- Flip the Red lever
- Get the Sewer Key (green key on the map)
- Unlock the gate blocking the Cosmic Vine
UFO Key (rebirth required)
Includes Homeless Alien dialogue before and after the gray key
- Flip the Blue lever
- Flip the Red lever
- Flip the Green lever
- Unflip the Red lever
- Flip the Purple lever
- Flip the Red lever
- Flip the Green lever
- Speak to the Homeless Alien
- Unflip the Green lever
- Unflip the Red lever
- Get the UFO Key (gray key on the map)
- Flip the Red lever
- Flip the Green lever
- Speak to the Homeless Alien again to finish the quest
After you get the keys
| Key | What it unlocks | Badge / bonus |
|---|---|---|
| Sewer Key | Gate to the Cosmic Vine shortcut | Cosmic Farmer Badge |
| UFO Key | Homeless Alien quest completion | Good Samaritan Badge (2× investor bonus) |
Tips
- Wrong lever? Leave the game or switch servers to reset — used keys do not reset.
- After flipping a lever, respawn to the surface and re-enter a manhole to reach the next switch faster.
- Find the manhole outside your plot — see Infrastructure for where progression unlocks the fence.
FAQ
Where is the Sell Lemons sewer maze?
Enter through any manhole on the main street — they all lead to the same underground maze with colored levers, locked doors, and both keys.
What is the Sewer Key lever order?
Blue ON, Red ON, Green ON, Red OFF, Blue OFF, Purple ON, Red ON — then pick up the green Sewer Key and unlock the gate to the Cosmic Vine.
What is the UFO Key lever order?
Blue ON, Red ON, Green ON, Red OFF, Purple ON, Red ON, Green ON, talk to the Homeless Alien, Green OFF, Red OFF, collect the gray UFO Key, Red ON, Green ON, then speak to the Homeless Alien again. Rebirth is required.
Do I need rebirth for the UFO Key?
Yes. The UFO Key only appears after you have progressed through rebirth and the alien investor storyline. You can still get the Sewer Key without rebirth.
Why rejoin the server between keys?
Doing the Sewer Key and UFO Key back-to-back in one server can leave levers stuck. Join a fresh server before starting the second key route.
Does leaving the game reset the sewer puzzle?
Yes — leaving resets lever progress in the maze. Keys you have already used stay consumed forever, so finish each key run before you quit.