Standing on Trailtrow Hill, Repentance Tower formed part of a chain of defense posts which warned against English raiding parties who crossed the border.
This three-storey tower house was founded by Sir John Maxwell of Terregles in the mid 16th century.
In 1548 an English force challenged the Douglases at Durisdeer, who were under the charge of Sir John. The night before the battle, he had been bribed to change sides in exchange for the hand of Agnes Herries and the title Lord Herries. His treachery, however, cost the lives of 12 of his kinsmen, who had been held at Carlisle Castle as hostages, one of which was his 12-year-old nephew. Maxwell was said to have built the tower as a sign of his remorse.
Another version of the tale has it that Repentance Tower was so-called because Lord Herries built Hoddom Castle out of stones from Trailtrow Chapel.