The "Martinstor" (Martin's Gate) belongs to Freiburg's first city fortifications built at the beginning of the 13th century.
It is older than the other remaining fortification tower gate, the "Schwabentor" (originally there were four towers). The first documentary mention of the tower was in 1238: "Porta Sancta Martini".
The Martinstor was joined on the land side to the city wall. The defense passage was six meters above the ground. A 12 meter wide and 5 meter deep bridged moat was located outside the tower.
Originally, the Martinstor was much smaller and had a stocky appearance. It was, along with the Schwabentor, almost torn down at the end of the 19th century. Following many false starts, the tower's renovation finally began in the summer of 1901.
The architect Carl Schäfer tripled the height of the tower (from 22 to 60 meter) and carried out the reconstruction in the 15th century style. He used colored glass tiles for the roof (today it is made of copper). Schäfer also designed the bordering structures which are built in the Late Gothic and Renaissance styles.
The original land side wall painting (a German imperial eagle over Freiburg's coat of arms) was replaced in 1951 with a Baroque sandstone slab depicting the Roman double eagle.
A tablet was mounted on the north side of the tower in 1988 in memory of the numerous victims of the witch hunts. Among the victims named are three Freiburg women who were convicted in 1599 of being witches and beheaded.