Suggestions for cardio that’s easy on the knees?

Hey folks, I’m in my 30s and used to be pretty active mainly soccer and Muay Thai. Over the last couple of years my knees have become a lot more sensitive, to the point where even jogging eventually starts to hurt after a few weeks. Because of that, I stopped playing and training, but I’m really missing the cardio and movement.

Does anyone have recommendations for good cardio exercises that are knee-friendly? I’m open to gym or outdoor options. Ideally something enjoyable that doesn’t feel like just grinding on a treadmill.

If anyone has been in a similar boat after high-impact sports and found something that worked for them, I’d love to hear it. Any advice is appreciated.