Notes:
1. Training grounds: training is free (10 creatures per week).
2. Altar of Elements: additionally grants +1 to spell power for Witches and +1 to attack for Assassins (since elemental magic doesn't work for them).
3. Temple: undead transformation is disabled. Instead, all ghosts lost by the player immediately become available for recruitment. When built in multiple cities, all ghosts are recruited from a common pool (a single pool for all Necropolises with a Temple).
4. Traveler's Hut: additionally, all Orc heroes receive +10% to movement range.
5. Slave Market: creatures can be sold for 200% of their cost.
6. Sparkling Fountain: additionally grants +3 to luck for visiting heroes until the end of the week.
7. Treasury: functions like farms, doubling the weekly growth of Djinns (in addition to +500 gold per day).
8. Sacrificial Pit: all Demon heroes receive +1000 experience weekly.
9. School of Runes: upon construction, runes of levels 1-5 become immediately available (depending on the hero's skill).