Pink Floyd’s The Wall is implied to be an endless loop. The final song, Outside the Wall, ends with the words “Isn’t this where…”, and the album begins with the words “… we came in?” with a continuation of the melody of the last song, hinting at the cyclical nature of Water’s theme.

The Wall

This article is about the Pink Floyd album. For the film based on the album, see Pink Floyd – The Wall. For other uses, see Wall (disambiguation).

The Wall is the eleventh studio album by English rock band Pink Floyd, released as a double album on 30 November 1979 through Harvest and Columbia Records. Concieved during the In The Flesh tour, recording for the record spanned about a year, from December 1978 to November 1979, and took place in France, England, New York, and Los Angeles. It was produced by Bob Erzin, who helped to refine the concept and bridge tensions during recording. Some of the outtakes from the recording sessions were used on the band’s next album, The Final Cut (1983).

A rock opera and a concept record, its story …
Read More
Source: https://wikipedia.org/wiki/The_Wall#Concept_and_storyline