Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_16577990_1 ( size_in_km² INTEGER, central_forest_reserve VARCHAR )

### Question ###
What is the size of Itwara central forest reserve?

### Accurate SQL ###

SELECT MIN(size_in_km²) FROM table_16577990_1 WHERE central_forest_reserve = "Itwara"