Original german name: Kavalier Hauptstein = http://www.festungsforschung-mainz.de/zweiter-befestigungsring/kavalier-hauptstein/
Englaish name: Hauptstein Cavalier.

The German original name: Limeswachturm Wp 3/26.
The German alternate name: Römerturm Idstein-Dasbach.
Source: https://de.wikipedia.org/wiki/Limeswachturm_Wp_3/26

The original German name: Limeswachturm Wp 3/26.
The alternate German name: Römerturm Idstein-Dasbach.
Source https://de.wikipedia.org/wiki/Limeswachturm_Wp_3/26

The english name: Caponier V.

The historical building and the part of Mainz Fortress.
The english name: Old Arsenal.

The english name: Templar Gate.

Original german name: Kaponniere Malakoff.
Alternate german name: Fort Malakoff.
English name: Malakoff Caponier.

The german original name: Kavalier Prinz Holstein.
The english name: Prince Holstein Cavalier.
Source http://www.festungsforschung-mainz.de/zweiter-befestigungsring/kavalier-prinz-holstein/

The original German name:Limeswachturms Wp 12/77
source: https://de.wikipedia.org/wiki/Kastell_Buch#Limesverlauf_ab_Kastell_Buch

Bastion Alexander is the part of Manz Fortress and tourist attractions.