Ebel City is the largest city in Basel. It is located on Level 4 and is always available from the start of the game. Each hex is a different location within Ebel City.

11th Street
"People and goods flow freely through this popular waypoint en route to Chandelier. The Base stands on 11th Street."

Sweet Home
In your home base "Sweet Home", you can do several things:

The mailbox will have rewards for completing side quests with the Guild
You can rest on the couch, which will restore health.
You can save at the chalkboard.
You can change your characters' clothes with the wardrobe.
You can check the bestiary for enemies, weaknesses and drop tables.
After the main story mission is done for each chapter and you enter the base, you will receive a prompt if you'd like to advance to the next chapter. If choosing no, you can later advance to the next chapter from the chalkboard.

Cheyenne Street
"People and goods flow freely through this popular waypoint en route to Chandelier. The Guild is located on Cheyenne Street."

The Guild
The Guild provides you with several options, where the main option is access to side missions. If you check the Guild's board during gameplay, you will find notices for jobs. Since you are only allowed three activate side quests at a time, once you complete a couple, return to the Guild to see if more are available. If there are any unfinished side quests when you try to advance to the next chapter, you will be alerted of that.

The Guild will also let you exchange 10x of a colored energy hex into a corresponding Energy Station. These stations can be placed on any Thoroughfare hexagons on the world map, allowing you to save, rest and teleport back to base (If the whole level has been unlocked).

Razzle Street
"People and goods flow freely through this popular waypoint en route to Chandelier. Razzle Street features a number of shops."

Ebel City Shop
The Ebel City Shop consists of three different parts: The Shop, The Scrapper, and The Tinkerer.

The Shop: Buys and sells items. More items become available as you progress the story, so make sure to come back often to see what is for sale.
The Scrapper: This is where you can bring items to be scrapped. Items that have no other use than being scrapped, will say so in the description. It is possible to scrap most items in the game however, so if you have an abundance of certain items, scrapping them for more basic resources could be useful.
The Tinkerer: This is where you pay for the tinkerer to do your item crafting. Each item requires a certain amount of resources and rubies to make, many which can be purchased in the nearby shop. Like the shop, as you progress the story, he will be able to make more and more items. (Every Tinkerer will have different items they can make, this one being Tier 4)
Boutique Lily
This is where you can buy clothes and accessories for each of the characters. It is also one of the only three places where you can change clothes. As you progress the game, more and more clothes and accessories will be unlocked for you to purchase, in addition to pieces of clothing you find on the world map.