The Mid Line

Copenhagen had a coastal defence in three lines
The second and middle line consisted of
:

The coastal battery Charlottenlund Battery” (later referred to as a fort)
The naval
fort “Middelgrunds Fort”
The
coastal battery “Kastrup Battery” (later referred to as a fort)

The defence line also got two coastal batteries in the left and right wings.  
The coastal battery “Hvidöre Battery” in the north  
The coastal battery “Avedöre Battery” in the south.