The seat of the Barons Rossmore was Rossmore Castle, County Monaghan.

Entity and relation annotations:
id: 0
type: entity
value: text: Rossmore Castle
labels: <Location>
id: 1
type: entity
value: text: County Monaghan
labels: <Location>
id: 2
type: entity
value: text: the Barons Rossmore
labels: <Person>
type: relation
to_id: 1
labels: Location:located_in:Location
from_id: 0
type: relation
to_id: 0
labels: Person:resides_at:Location
from_id: 2