Table:
text: List of Sites of Special Scientific Interest in Derbyshire
Sites
Sites
Site_name Reason_for_designation_Biological_interest Reason_for_designation_Geological_interest Area_Hectares Area_Acres Coordinates_Grid_ref Year_in_which_notified Other_designations Map_Citation_
Breadsall Railway Cutting   4.9 12.0 52°57′11″N 1°25′08″W﻿ / ﻿52.953°N 1.419°W ,     SK391397 1986 GCR, LNR, WT Map
Calke Park   71.1 175.8 52°48′04″N 1°27′58″W﻿ / ﻿52.801°N 1.466°W ,     SK361227 1992  Map
Calton Hill   5.2 12.7 53°14′20″N 1°49′41″W﻿ / ﻿53.239°N 1.828°W ,     SK116713 1951 GCR Map
Carver`s Rocks   16.7 41.2 52°48′00″N 1°30′43″W﻿ / ﻿52.8°N 1.512°W ,     SK330226 1963  Map
Castleton   837.3 2069.1 53°20′13″N 1°48′11″W﻿ / ﻿53.337°N 1.803°W ,     SK132823 1954 GCR, NP, NT Map
Cawdor Quarry   4.7 11.7 53°08′28″N 1°34′30″W﻿ / ﻿53.141°N 1.575°W ,     SK285605 1963 GCR Map
Chatsworth Old Park   72.5 179.2 53°13′01″N 1°36′22″W﻿ / ﻿53.217°N 1.606°W ,     SK264689 1998 NP Map

Question: What is the number of acres at Castledon included in the list of Sites of Special Scientific Interest in Derbyshire?