Looking out across the battle scarred environs of the Border Kingdoms stand several large stone built towers. These are almost like mini-keeps, holding them will provide some bonuses to your guild, but nothing like those of a full keep. You also can’t build anything around a tower.
These locations do though provide something that smaller guilds can still take and hold even if they perhaps don’t have the manpower or resource to hold a Battle keep. Like the keeps, these towers will have periods when they are open for attack. This means those precious bonuses they provide will have to be defended through force of arms.