Original: The tower stands for the castle of Stargard, the longtime seat of the dukes of Mecklenburg since its construction in the 13th century; it remains the northernmost mountain-top castle in present-day Germany.
Simplified: The tower stands for the castle of Stargard, the longtime home of the dukes of Mecklenburg since it was built in the 13th century; it remains the northernmost mountain-top castle in present-day Germany.