What is garrison tower?

As an AI language model, I don't have any specific information about a particular garrison tower. However, a garrison tower is typically a defensive structure built within a military base or fortress. They were commonly used during the medieval period and served as a lookout point for soldiers to observe and defend against enemy attacks. Garrison towers were often built high up and provided strategic advantages for armies in terms of communication, surveillance, and shelter. They could also serve as a symbol of power and authority, indicating the presence of a military force in the surrounding area.