We can use
docker volume ls
List all dossiers.
When using inspect on OSx to view, as a result, we can't find the Mountpoint directory when we get to the Mac?

docker volume inspect neip_www
[
    {
        "CreatedAt": "2018-05-12T15:30:17Z",
        "Driver": "local",
        "Labels": {
            "com.docker.stack.namespace": "neip"
        },
        "Mountpoint": "/var/lib/docker/volumes/neip_www/_data",
        "Name": "neip_www",
        "Options": null,
        "Scope": "local"
    }
]

This is because actually the directory is on the Docker for Mac VM.
We can connect to the VM through the screen command

screen ~/Library/Containers/com.docker.docker/Data/com.docker.driver.amd64-linux/tty

available through
Ctrl-a k to leave.
Ctrl-a d to background.
screen -r lists background ttys.
screen -r [number] reconnect