I have two adult cats. Both live indoors in an urban setting, but are allowed outoors.

One I have leash trained,on a long rope, with a small dog harness (yes, he is over-weight).

The other is now fearful of straying off very far from our back yard. I seem to recall she was very easy to train to "stay put". But, I suspect every cat is different and there may be "temptations" to lead them away.

If you consider a leash, it works best if they get used to it as kittens.