All castles in Heroes 3.

Much depends on who you are playing against and which faction you are using. The Necropolis can manage for the first two weeks without hiring troops in the city; this tactic is viable for them. However, it is not suitable when playing against the Necropolis. When I play as the Necropolis, I act according to the circumstances – either focusing on troop development or on accumulating resources, depending on the city's location and its surroundings.