The idea of trudging around in a sewer may not seem the most appealing idea, but if you can get over your initial reservations, you’ll be able to soak up the rewards.
Where to Find the Sewer:
The Sewer is located on the south side of Pelican Town. To get there, head south through your farm in the forest. Keep heading south and cross the rickety bridge at the river. Eventually, you’ll see a set of stairs that leads to the gated entrance of The Sewer.
The Sewer’s Benefits:
Willing to take the plunge into the abyss? If so, you’ll find the Sewer offers many advantages not found above ground.
For one, you can find a little friend named Krobus down here. He is a Shadow Brute, but, unlike the ones in the mines, will not harm you. On the contrary, Krobus sells wares such as the iridium sprinkler used to water multiple plants at a time (and used to set up the best greenhouse layout in late game). You can befriend Krobus and invite him to be a roommate in your house. Unfortunately, he cannot be a spouse.
Opening The Sewer also puts you one step closer to the Mutant Bug Lair which you need to enter in order to complete the Dark Talisman Quest (which makes the Witch’s Swamp accessible).
The Key to the Sewer:
To unlock The Sewer in Stardew Valley, get ready for a lot of digging, mining, and defeating monsters because you’ll need artifacts and minerals.
You’ll first hear about the key during a cutscene in the Cindersap Forest. To see it, you’ll need to visit on certain days of the week (Monday, Thursday, or Sunday) between 9 am and 4pm. This cutscene is not available until after the 11th day of Spring in year 1.
Thankfully, you only need 60 artifacts or minerals total to donate to the Museum. Once you’ve donated these, Gunther will give you a Rusty Key. You’ll find it in your inventory tucked inside your Wallet. Once at the entrance, simply right-click on The Sewer and meet your new mercantile friend!
Unlocking the Sewers is not particularly difficult, but will take time. Next time you’re in the mines or out and about, take the time to scan for artifacts and minerals. Resist the temptation to sell them for quick cash. Your patience may earn you an even greater reward.