The hypothetical Oort Cloud is not a good way to describe a boundary or destination. We only know of circumstancial evidence for it. There have been no direct observations. We believe that it is extraordinarily sparse. Therefore, its beginning and end would be poorly defined.
https://en.wikipedia.org/wiki/Kuiper_belt
Everyone* knows about the Kuiper Belt, of course, but we are looking into at least two other “reservoirs” of TNOs between those named ones.