Mount a non encrypted ZFS partition from a backup on another FreeBSD system

r@bsd:~ $  geom disk listGeom name: cd0Providers:1. Name: cd0   Mediasize: 0 (0B)   Sectorsize: 2048   Mode: r0w0e0   descr: QEMU QEMU DVD-ROM   ident: (null)   rotationrate: unknown   fwsectors: 0   fwheads: 0Geom name: ada0Providers:1. Name: ada0   Mediasize: 21474836480 (20G)   Sectorsize: 512   Mode: r3w3e6   descr: QEMU HARDDISK   ident: QM00003   rotationrate: unknown   fwsectors: 63   fwheads: 16Geom name: ada1Providers:1. Name: ada1   Mediasize: 21474836480 (20G)   Sectorsize: 512   Mode: r0w0e0   descr: QEMU HARDDISK   ident: QM00005   rotationrate: unknown   fwsectors: 63   fwheads: 16

ada1 contains multiple partitions.

r@bsd:/home/r # zdb -l /dev/ada1p4------------------------------------LABEL 0------------------------------------    version: 5000    name: 'zroot'    state: 0    txg: 175    pool_guid: 16431233065571143512    errata: 0    hostname: 'bsd13.4'    top_guid: 15815179069858987969    guid: 15815179069858987969    vdev_children: 1    vdev_tree:        type: 'disk'        id: 0        guid: 15815179069858987969        path: '/dev/ada0p4'        whole_disk: 1        metaslab_array: 131        metaslab_shift: 29        ashift: 12        asize: 19047907328        is_log: 0        create_txg: 4    features_for_read:        com.delphix:hole_birth        com.delphix:embedded_data    labels = 0 1 2 3

How can I mount /dev/ada1p4 in /mnt ?