Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_298550_1 (area__km²_ INTEGER, capital VARCHAR)
### Question:
What is the highest value of area when capital is San Juan?
### Answer:
SELECT MAX(area__km²_) FROM table_298550_1 WHERE capital = "San Juan"