Paul McCartney Films River Under Overpass in Oklahoma

Paul McCartney left the 'Strawberry Fields' behind for a different idyllic location -- an overpass in Tulsa, Oklahoma ... no, we aren't kidding.

The singer-songwriter shared a video on TikTok Thursday of himself in the Sooner State on the bank of a river ... sitting on a slope set just a bit down from a huge highway overpass.

PM says he's got a beautiful view of the "pretty big, groovy" Arkansas River ... and, he flips the camera to show his followers the view he's looking at.

It's a peaceful place ... though we think beauty might just be in the eye of the beholder here -- 'cause the graffiti on a nearby stone edifice and the overpass behind Paul doesn't exactly want to make us "Twist and Shout."

Paul then says hello to a butterfly he apparently saw -- though it doesn't really show up on the video -- and says it feels like springtime ... even though it's October.

McCartney's currently on his "Got Back" tour ... and, he played in Tulsa at BOK Center earlier this week. He's headed down to Texas for a show at the Alamodome tomorrow before continuing on to New Orleans, Atlanta, Nashville and many more popular arenas across the country.