The interiors and final room plans are believed to be the work of Pearce, however the long suite of reception rooms along the ground-floor garden front, are not in the strict palladian tradition. Such a mansion as Castletown, in Italy, would have been a town Palazzo rather than a country villa. The long suite of room with a central salon, terminating with smaller rooms at the end of the enfilade is more typical of the suites of state rooms in English country houses at the time. The central saloon at Castletown opens into the two-storey entrance hall, which is traversed by a corridor running the length of the mansion; the principal staircase is situated in an adjoining hall to the side of the great hall. In this layout of state rooms, hall and staircase Castletown is similar to Blenheim Palace, which Pearce had studied while a student of Vanbrugh. (While Pearce designed the staircase it was not actually constructed until 1760, some 28 years after his death.)