I just saw James Mangold’s Bob Dylan-goes-electric history lesson “A Complete Unknown,” the music biopic that wears its subject’s impenetrable nature as its raison d’être.

Importantly, the kink in cis fats means they cannot be tightly packed -- a positive feature for avoiding impenetrable clogs.

A separate thread in the series follows the McConville children over the decades, as they fight an impenetrable code of silence to uncover the truth about their mother.

South Korea’s frontier with the North is an almost impenetrable barrier, the heavily mined and fortified Demilitarized Zone.

Suriname has some of the most impenetrable jungle in the world, covering 93% of the country.