There are multiple records relating to the City Walls, all organised under the grandparent record (MYO3631) City Walls in entirety. Historically, the City Walls were split into three sections for the HER, which reflected their national listing (MYO1715, MYO1734, MYO1733).
In an effort to make entries more specific additional records have been created beneath the three sections listed above as child records. These relate to specific features such as stretches of wall and rampart, towers and bars. Exploring the interactive map can be helpful if you are not familiar with the different sections of the City Walls, or with the names of the towers and bars.