Reaching the Sunless City in Outer Wilds is one of the most fascinating and challenging tasks in the game. It requires a blend of timing, environmental awareness, and precise navigation. The city is hidden deep within the Ember Twin, one of the two closely orbiting planets in the Hourglass Twins system. Unlike other locations that are visible or easy to land on, the Sunless City is concealed beneath the surface and becomes gradually more accessible as sand drains from Ash Twin and fills Ember Twin. This makes exploring the city a race against time, creating a uniquely immersive experience for any player who dares to investigate its secrets.
Understanding the Hourglass Twins
Ember Twin and Ash Twin
Before you attempt to reach the Sunless City, it’s essential to understand the relationship between Ember Twin and Ash Twin. These two planets orbit extremely close to one another, and during each time loop, sand flows from Ash Twin to Ember Twin. This process slowly buries some locations while uncovering others, including the entrances to the Sunless City.
Since the sand transfer starts immediately when the time loop begins, timing is crucial. If you wait too long, certain areas will be inaccessible. If you arrive too early, entrances may still be blocked. Knowing when and where to land is vital for success.
Preparing for the Journey
What You Need
There are no items or upgrades required to access the Sunless City, but having a strong understanding of the spaceflight and jetpack mechanics will help you avoid damage or missteps during descent. You should also make sure your oxygen tank is full before entering the cave systems, as it’s easy to get turned around underground.
Here are some quick preparation tips:
- Land early in the loop to maximize exploration time
- Monitor oxygen and fuel levels regularly
- Use scout launcher to test tight or dark areas before entering
- Familiarize yourself with landmarks on Ember Twin
Best Time to Land
Try to land on Ember Twin within the first 3-5 minutes of the time loop. This gives you the best chance to reach the entrances to the cave system before they fill with sand. If you’re too late, the caves may be buried, forcing you to restart the loop and try again.
Locating the Sunless City Entrance
Main Entrance via the High Energy Lab
One of the most reliable ways to enter the Sunless City is through a cave system near the High Energy Lab path. This entrance is located on the equator of Ember Twin and is best approached from orbit using the planetary map to track landmarks.
To find the cave:
- Land near the equator of Ember Twin, ideally just west of the center crater.
- Look for a cave entrance marked by small stone structures or Nomai ruins.
- Enter and carefully descend using your jetpack to avoid fall damage.
- Follow the tunnels downward, staying ahead of the rising sand.
This path will eventually take you through a maze of corridors leading to the main chambers of the Sunless City. Keep an eye out for small passages and side paths that loop back into the main rooms if you get lost.
Alternative Entrances
There are multiple entrances to the Sunless City scattered across Ember Twin. While the High Energy Lab path is reliable, you can also try entering through:
- The Gravity Cannon cave located near the North Pole, useful early in the loop
- The Anglerfish Fossil cave contains a winding path that connects to deeper areas
- The southern spiral path leads directly to the bottom chambers but becomes buried quickly
Each of these routes offers different views of the city, and some may be blocked or inaccessible depending on how much time has passed. Exploring all of them across several loops can help you form a full mental map of the city’s layout.
Navigating the Sunless City
Main Hubs and Chambers
Once inside, the Sunless City reveals a web of interconnected chambers, each designed by the Nomai to serve a specific purpose. Key areas include:
- The Stepping Stone District the primary entrance and center of the city
- The Eye Shrine District filled with clues about the Eye of the Universe
- The School District contains valuable logs and Nomai communication
- The Anglerfish Overlook District helps with puzzle solving later in the game
Use your translator frequently to gather important story details, and watch for glowing lights to guide your direction. The scout launcher is also useful for checking narrow passages or dark corridors before entering.
Hazards and Environmental Challenges
The Sunless City becomes increasingly dangerous as the loop progresses. Here are some hazards to be aware of:
- Rising sand will fill tunnels and cut off your exit if you take too long
- Limited oxygen some chambers are sealed and offer no fresh air sources
- Falling hazards deep pits and narrow ledges are easy to miss in the dark
To maximize your time underground, take note of shortcut passages, oxygen refill spots, and safe chambers where you can stop and plan your next move.
Key Discoveries in the Sunless City
Unlocking Game Secrets
The Sunless City is rich with lore that explains the Nomai’s purpose, their fate, and their connection to the Eye of the Universe. While you may not need to visit every district, doing so enhances your understanding of the game’s mystery and prepares you for later challenges.
Critical information found in the city includes:
- The purpose of the Ash Twin Project
- Why the Nomai abandoned their search for the Eye
- Details about the Anglerfish and how it behaves
- Timeline markers for when the city was last active
Take time to explore every mural, projection stone, and console you find. They provide essential context for the final stages of your journey through the solar system.
Connecting the Dots
Information from the Sunless City helps piece together the full puzzle of the time loop and the broader storyline of Outer Wilds. Returning here multiple times with new knowledge unlocks even more meaning from earlier discoveries. Pay close attention to what each Nomai log says and how they relate to other areas like the Ash Twin Core, the White Hole Station, and the Quantum Moon.
Final Tips for Reaching the Sunless City
Practice Makes Perfect
Don’t be discouraged if you miss the entrance or get buried in sand during your first few attempts. The game is designed to be replayed and experimented with. Try different routes and approaches until you find a path that works for you.
Keep a Mental Map
The city’s structure can be confusing at first, especially with its winding tunnels and multi-level chambers. As you explore, mentally map out key landmarks and return paths. Knowing how to reach oxygen refill points or shortcuts to the surface can be the difference between life and death.
Use the Pause Between Loops
After each loop ends, take a moment to review your ship’s log. The information recorded about the Sunless City will help clarify your objectives and reveal any areas you’ve missed. Use this log to plan your next approach and refine your path into the underground ruins.
Exploring the Sunless City is one of the most rewarding parts of Outer Wilds. With its deep lore, clever environmental design, and race-against-time urgency, it challenges players to think strategically and act quickly. Follow the steps above, stay patient, and the city’s secrets will soon be yours to uncover.