The Hidden Bunker is a special map modifier that can appear on the Spaceport map in Arc Raiders. When it is active, a locked bunker complex becomes available west of the Departure Building. The bunker does not open automatically. Players in the raid must complete a shared objective to unlock it.
In general, the Hidden Bunker turns a normal Spaceport raid into a more focused objective run. There are fewer standard extraction options, fewer fast travel systems, and more pressure from ARC enemies. Most players treat this modifier as a high-risk, high-attention activity rather than a casual loot run.
The raid timer is still capped at 40 minutes, so time management matters a lot when this modifier is active.
How Do You Unlock the Hidden Bunker?
To unlock the Hidden Bunker, players must activate four rooftop antenna dishes. These antennas spawn on rooftops near the center of the Spaceport map. Their exact locations change every raid, but they are always on elevated buildings.
Usually, the easiest way to find them is by opening the map and zooming all the way out. Any antenna that has not been activated will show an icon. Once an antenna is completed, its icon disappears.
Important thing to know:Progress is shared across the entire lobby. One player can activate all four antennas, or multiple players can each do one or two. It does not matter who activates them, as long as all four are completed.
Because of this, most players keep an eye on progress notifications. Sometimes the bunker opens without you personally touching an antenna, simply because other players finished the job.
What Happens When You Activate an Antenna?
Each antenna must be interacted with twice.
First Interaction: Alarm and Enemies
When you activate an antenna for the first time, it sends out a short alarm. This causes Wasp and Hornet ARC units to spawn nearby. You must defeat these enemies before the antenna can be completed.
In practice, this is the most dangerous part of the antenna process. The noise and combat often attract other players, especially in the middle of the map. Most experienced players clear the area first or activate antennas quickly and reposition.
Second Interaction: Completion
After the enemies are cleared, you interact with the antenna a second time. This marks it as completed. A progress message appears for everyone in the lobby, showing how many antennas are done.
Once all four antennas are completed, the Hidden Bunker becomes accessible immediately.
Where Is the Hidden Bunker Located?
All bunker entrances are located west of the Departure Building. There are multiple entrances, but they are close together and easy to recognize once the bunker is unlocked.
The bunker does not require any extra key items to enter. If you are nearby when the final antenna is completed, you can move in right away. If you are far away, expect that other players may already be heading there.
Usually, the first few minutes after the bunker opens are the most contested.
What Is Inside the Hidden Bunker?
The Hidden Bunker is not just a loot room. It is a data retrieval objective with strong enemy defense.
Inside the bunker, players will find several terminals. These terminals are used to download data. Each terminal follows the same basic process:

1. Interact with the terminal to start a download.
2. The download progress can be seen on the terminal screen.
3. Once the download completes, you must interact with the terminal again within a limited time to retrieve the data.

There are four terminals, and each one must be used separately. You cannot retrieve all data from a single terminal.
In general, this means players need to stay inside the bunker longer than usual, which increases risk.
What Enemies Defend the Bunker?
The Hidden Bunker is guarded by heavy ARC units:

• Two Bastions
• One Bombardier

These enemies make the bunker much harder than most surface-level encounters. Bastions can absorb a lot of damage, and the Bombardier adds constant pressure with explosives.
Most players do not try to rush all enemies at once. Instead, they pull enemies into choke points, use cover, and manage ammo carefully. If you enter the bunker without enough supplies, you will usually have to leave early or risk being overwhelmed.
How Does the Hidden Bunker Change the Map?
When the Hidden Bunker modifier is active, several other systems are affected:

• Fewer active Return Points
• No active Raider Hatches
• Rooftop antennas must be activated
• Data retrieval becomes a primary objective
• Spaceport difficulty increases from 3/5 to 5/5
• Trials multiplier is 2x

In practice, this means movement is slower and mistakes are more costly. You cannot rely on fast exits or quick repositioning. Most players plan their route more carefully and avoid unnecessary fights.
Is the Hidden Bunker Worth Doing?
Whether the Hidden Bunker is worth doing depends on your goal.
For players focused on challenges, progression, or coordinated gameplay, it is usually worth attempting. The shared objective design encourages interaction, both cooperative and competitive.
For solo players or lightly geared players, the bunker can be risky. You are likely to encounter both strong ARC enemies and other players waiting for an opportunity.
Most experienced players recommend entering the bunker only if:

• You have enough ammo and healing
• You are aware of nearby player activity
• You have an exit plan once the data is retrieved

Common Mistakes Players Make
Based on common behavior, these mistakes happen often:

• Activating an antenna without checking surroundings
• Starting a bunker download with low ammo
• Staying too long after retrieving data
• Assuming other players will cooperate
• Ignoring map progress notifications

The Hidden Bunker rewards awareness more than raw firepower.
Final Thoughts on the Hidden Bunker
The Hidden Bunker is one of the more structured objectives in Arc Raiders. It pushes players to interact with the map, manage time, and respond to shared progress.
In general, it works best when you treat it as a tactical objective rather than a loot rush. Most players who struggle with it are the ones who rush in without preparation.
If you approach it calmly and understand how the antennas, terminals, and enemies work, the Hidden Bunker becomes predictable and manageable.
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