Castle Rising's population is 225.
There is no specific collective noun for the noun risings; a general collective related to the context of those risings would be use. Some examples are a series of risings (armed conflicts) or a group of risings (landforms).
The population of Dover castle is 28,156.
The population of Castle Eaton is 235.
The population of Castle Carrock is 303.
Elmley Castle's population is 497.
Castle Hedingham's population is 1,000.
The population of Castle Cary is 2,096.
Castle Gresley's population is 1,566.
The population of Castle Vale is 10,000.
The population of Castle Acre is 800.
Castle Harlan's population is 25.
The population of Bishop's Castle is 1,630.