Stronghold 2 Castle Structures Buildings
Wooden Wall
This is essentially the equivalent of walls in the earlier Stronghold games where troops can destroy them. Wooden wall provides similar protective abilities to Stone wall except for the fact that attacking troops can just destroy it without any siege equipment. You can use either wooden platforms or stone stairwells to move troops up onto your wooden wall.
Cost: 1
Resource: Wood
Stone Wall
Stone walls are much stronger than wooden walls. They can't be destroyed by troops and can only be destroyed by siege equipment. Stone walls also offer a height advantage over wooden walls as well.
Cost: 1 , 2 or 3
Resource: Stone
Stairwell
Stone Stairwells allow your troops to gain access to either your wooden or stone walls. Despite the height difference, these stairwells will still allow access to wooden walls. There are also two doors at the bottom on corners, so these can be rotated around to show either both or only one in you place it against a wall for instance.
Cost: 10
Resource: Stone
Wooden Platform
Wooden platforms allow your troops to gain access to your walls. Despite a height difference they can also be placed against Stone walls which will allow your troops to gain access to those as well.
Cost: 10
Resource: Wood
Lookout Tower
Lookout towers are cheap although do not offer much protection against siege equipment. They are mainly useful against troops, although don't hold many troops in the tower. They can also be destroyed by tunnelling.
Cost: 40
Resource: Stone
Bastion
Thought not that tall, the Bastion will allow you to station a medium sized garrison. You can also station siege equipment such as Mangonels or ballistae. Tunnelling does not affect the Bastion.
Cost: 60
Resource: Stone
Square Tower
Square Towers provide a good amount of space for ranged troops to fire at the enemy from. They also provide a decent level of protection against siege equipment. Mangonels and Ballistae can be placed on the top of the Tower to fire further at enemy units. In addition to this, you can also place an Archer on the middle floor who will fire out of the slit in the wall.
Cost: 100
Resource: Stone
Round Tower
Round Towers are slightly stronger than Square Towers, but offers much of the same functionality. You can place siege equipment on the top such as Mangonels, and you can also station troops on the middle floor of the tower who will be able to fire out of two arrow slits in the wall.
Cost: 120
Resource: Stone
Great Tower
The Great Tower is the most expensive to place out of all towers, however it is the hardest to destroy and also the strongest. You can place siege equipment on the top of the tower, and there is a vast amount of space on the tower where you can attack units from. There are four arrow slots on the middle floor that units can use to fire at enemy units, and it is also immune to tunnelling.
Cost: 180
Resource: Stone
Square Tower with Hoarding
This tower is virtually identical to the Square Tower, apart from the Hoarding placed on the top which protects your units against missile fire or other forms of attack. There is a slit to fire out of on the middle floor as well, if you placed ranged units there.
Cost: 20, 100
Resource: Wood, Stone
Round Tower with Hoarding
Similar to the Round Tower, the main difference is that the Hoarding protects units who are stationed on top of the tower. There is also an arrow slit for any ranged units that are stationed on the middle floor of the tower.
Cost: 20, 120
Resource: Wood, Stone
Wooden Gatehouse
Wooden Gatehouses can be destroyed by attacking troops very easily, although it is cheap to construct. It does not withstand much force at all. To open/close it, left click on it, then left click on the open/close button. It will automatically close when enemies are nearby.
Cost: 20
Resource: Wood
Small Gatehouse
A small Gatehouse is built out of Stone and is much more protective than the more Wooden Gatehouse that will be destroyed simply by attacking troops. This is a much smaller version of the Large Gatehouse, and the only real difference between the two is that there is not as much space for missile troops. It can also be destroyed easier by siege equipment, for example battering rams. To open/close it, left click on it, then left click on the open/close button. It will automatically close when enemies are nearby.
Cost: 25
Resource: Stone
Main Gate
The main Gate is a more powerful version of the Small Gatehouse. This is much larger and much stronger against siege equipment such as Catapults. This allows your troops access in and out of your walls. It's the second strongest Gatehosue, second only to the Large Gatehouse. To open/close it, left click on it, then left click on the open/close button. It will automatically close when enemies are nearby.
Cost: 50
Resource: Stone
Large Gatehouse
This is the strongest Gatehouse in Stronghold 2. It is also the largest in size, and contains a drawbridge for you to place moat near. This also has the most space meaning that you can station the most troops nearby it, and it can also withstand the most siege equipment. To open/close it, left click on it, then left click on the open/close button. It will automatically close when enemies are nearby.
Cost: 80
Resource: Stone
Sally Port
This is probably the most useful castle structure of all. The Sally Port is essentially a Gatehouse but shows in your castle as a piece of wall to the enemy. It even shows up as wall to you until you choose to open it. This allows you to launch surprise attacks in your castle or make a quick escape. It can only be used once before its disguise is no longer useful and the enemy will see it is a secret gatehouse, although you can always remove it and place another one in its place. To open it, left click on it, then left click on the open/close button. However note that unless your Sally Port is open, your workers will not be able to use it as a normal Gatehouse and its use as such is therefore not recommended.
Cost: 40
Resource: Stone