Hi,
this year I bought me some new music instruments, one I like very much is the Irish bouzouki. It has four double strings, they make a very cool medieval sound. And strummed with a pick it can even compete with a small bagpipe regarding volume 😆 But my bouzouki also has a pickup, just in case 😁
There are several tuning variants. I currently have it tuned to ADAD, so you can play open chords by just sliding one finger over the fretboard 😀
I think the most common tuning is GDAE, like violin and mandolin.