user: Question: Which team has an Unknown coach and location of Athelstone?
Columns: ['Team', 'Coach', 'Home Ground', 'Location', 'Founded']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['The Cove SC', 'Danny Graystone', 'Club Cove', 'Hallett Cove', '1983']
SQL:

assistant: SELECT "Team" FROM "Table" WHERE "Coach" = 'Unknown' AND "Location" = 'Athelstone';