Keep

Due to constant raids from the Servants of the blood gods, Masked of Dantea started to employ large towers called keeps, which provide a hiding place for the people.

Each settlement has this, usually square tower. It's size, number of them, the design and whenever it is made out of wood or not, depends on the settlement. A city might have multiple large keeps made out of stone, while a village might have one made out of wood.

General layout:

The square tower, 5 meters wide and around 15 meters tall, hides 5 floors, each mostly empty. Soldiers store here some food, water, blankets, weapons, etc. for people hiding there. The top of the keep is a open wooden roof with machicolations, so soldiers can shoot down on the enemies.
The floors are either connected through stairs or ladders, the latter being better defense wise.

Additional information:

Hidden rooms/ entrances:

Many keeps have a tunnel that leads a few meters away from the keep, usually behind another building, allowing an escape in case the keep's defenses are broken.

Defenses:

The keep is usually guarded by 2 soldiers. During an emergency, as many as possible should retreat to the keep, while the others hold the attackers back.

Cost to build:

(Time, money, resources, workers, etc.)

Type

Keep