"Did You Know That There’s a Tunnel Under Ocean Blvd" is the title track of Lana Del Rey's ninth studio album and eighth major-label studio album. It serves as the record's lead single and was officially released on December 7, 2022.
The existence of the song was first revealed on September 1, 2022, when it was listed for sale alongside fellow Blue Banisters outtake "Fingertips" as well as a demo for "Arcadia". A snippet leaked the day after the "for sale" post was posted. The demo version of the song is 5:27.
On December 5, 2022, an insider revealed that the song would be released on December 7, 2022, stating that the song was "4:45" minutes long, describing the song as "insanely poetic, nostalgic, full of warmth, with stunning orchestral arrangement, rich vocal layering and large build up".