Two of the monuments (the knight and the war memorial) were not showing in the game. I tracked the problem down to the use of the "-" character in the names, which I replaced with the underscore ("_"). Below are the fixed attractions:
Obj=building
name=Knight_Monument
type=mon
intro_year=1700
intro_month=12
build_time=1000
chance=100
p****engers=20
dims=1,1,4
needs_ground=1
BackImage[0][0][0][0][0][0]=images/mon/knight-monument.0.0
BackImage[1][0][0][0][0][0]=images/mon/knight-monument.0.3
BackImage[2][0][0][0][0][0]=images/mon/knight-monument.0.2
BackImage[3][0][0][0][0][0]=images/mon/knight-monument.0.1
BackImage[0][0][0][0][0][1]=images/mon/knight-monument.1.0
BackImage[1][0][0][0][0][1]=images/mon/knight-monument.1.3
BackImage[2][0][0][0][0][1]=images/mon/knight-monument.1.2
BackImage[3][0][0][0][0][1]=images/mon/knight-monument.1.1
Obj=building
name=War_Memorial
type=mon
intro_year=1918
intro_month=11
retire_year=1950
retire_month=1
build_time=1000
chance=10
p****engers=20
dims=1,1,4
needs_ground=1
BackImage[0][0][0][0][0][0]=images/mon/war-memorial.0.0
BackImage[1][0][0][0][0][0]=images/mon/war-memorial.0.3
BackImage[2][0][0][0][0][0]=images/mon/war-memorial.0.2
BackImage[3][0][0][0][0][0]=images/mon/war-memorial.0.1
BackImage[0][0][0][0][0][1]=images/mon/war-memorial.1.0
BackImage[1][0][0][0][0][1]=images/mon/war-memorial.1.3
BackImage[2][0][0][0][0][1]=images/mon/war-memorial.1.2
BackImage[3][0][0][0][0][1]=images/mon/war-memorial.1.1
The relevant part of en.tab will need to be updated as follows:
Knight_Monument
Monument of a Knight
War_Memorial
War Memorial