Vintage Story has 5 designs of Hansa banners, this mod adds more banners, both the ground and wall variant. At the moment they're acessable via the creative menu, or can be discovered in ruins similar to vanilla. Most of the new art has a mythlogical vibe, some look like nation flags. Thanks to Vero for some of the better art pieces used.

Added rare ruins:
A destroyed clinic, fairly large, infected with locusts. (surface) 
An aztec style pyramid/temple, fairly large, infected with locusts. (surface)
A falling apart pagoda/small house, infected with locusts. (surface)
A small cave with handprint symbol. (underground)
an egyption style pyramid, very large, with many underground rooms teeming with locusts. (surface)
A partially collapsed tower. (surface)
A derilict small chicken pen. (surface)
The ruins of a castle. (surface)
An evil seeming hut, infected with drifters and a wolf. (surface)
An abandoned and rotting house. (surface)

let me know if the ruins are too rare.

Better Ruins:

If you have the mod Better Ruins installed you can craft the banners using the banner blueprint item from that mod similar to the recipe for the vanilla hansa banners.

Dana's Flags/Banners: 

If you have the mod Banners installed this adds 8 extra patterns that can be unlocked within that mod. For example to unlock the Yoahtl sun and stars pattern, drop a yoahtl banner onto the tool mode window.

To Do:

• Add more ruin schematics to gain more ways to find the banners, similar to other clutter items in the vanilla game.
• Add compatibility for the Banners & Flags mod when it's more complete.
• Add more art.
• A config file to allow disabling ruins and a way to select which art you want loaded into the game.
• Maybe accept art from others to add to the mod.
• Add achievements for use with the Achievements mod.