These are the buildings from Heroes of Might and Magic III that become available for construction once you aquire a Grail.
| Faction | Image | Description |
|---|---|---|
| Conflux | 
|
It increases the town's weekly creature growth by 50%, and generates 5000 gold every day. In addition, it places all spells in your mage guild (apart from Death ripple and Animate dead). |
| Fortress | 
|
It increases weekly creature growth by 50%, provides your kingdom with additional 5000 gold per day, and increases the attack and defense strength of a garrison hero by +10 when defending against a siege. |
| Rampart | 
|
It increases weekly creature growth by 50%, provides your kingdom with additional 5000 gold per day, and increases the luck of all allied heroes by +2. |
| Stronghold | 
|
It increases weekly creature growth by 50%, provides your kingdom with additional 5000 gold per day, and increases the attack strength of a garrison hero by +20 when defending against a siege. |
| Castle | 
|
It increases weekly creature growth by 50%, provides your kingdom with additional 5000 gold per day, and increases the morale of all allied heroes by +2. |
| Dungeon | 
|
It increases weekly creature growth by 50%, provides your kingdom with additional 5000 gold per day, and increases the spellpower of a garrison hero by +12 when defending against a siege. |
| Inferno | 
|
It increases weekly creature growth by 50% and provides your kingdom with additional 5000 gold per day. Every week hereafter will be a Week of the Imp. |
| Necropolis | 
|
It increases weekly creature growth by 50%, provides your kingdom with additional 5000 gold per day, and boosts the Necromancy skill of all allied heroes (who possess the skill) by 20%. |
| Tower | 
|
It increases weekly creature growth by 50%, provides your kingdom with additional 5000 gold per day, reveals the entire map and increases the knowledge of any defending hero by +15 (these spells points do not follow a hero who leaves the town). |