One would say it like this but the translations of this sentence on duo are wrong.
I think we should translate by : we turned AT the corner. Can anyone confirm that ?
No. It should be "turned around the corner". Duo forgot that "around" though.
Obviously turned around is the most literal translation, but personally I think all three (turned around, turned at, and turned the) are perfectly acceptable. I have definitely heard all three used.
That's true, all three are at least acceptable (while "turned the corner" is kind of ugly).