Woman in the Dunes (1964)

Good answers to this probably depend on what kind of movies you like (and TBH I have a hard time gauging whether something is obscure), but here's something that Wikipedia describes as a "Japanese New Wave avant-garde arthouse psychological thriller," about a man trapped in a house at the bottom of a sand dune and tasked with continuously shoveling the sand so that the house isn't buried. A singular work, enigmatic and mesmerizing.

(Others that I've rec'd here previously that might also fit the bill (they're described in more detail in the linked collection): RRR (2022), Attack the Block (2011), Red Rock West (1993), Straight to Hell (1987), Céline and Julie Go Boating (1974), The Spirit of the Beehive (1973), Seconds (1966), Ashes and Diamonds (1958), and any of these four Judy Holliday comedies.