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_name_26 (circuit VARCHAR, series VARCHAR)
### Question:
What is Circuit, when Series is ASTC Round 4?
### Answer:
SELECT circuit FROM table_name_26 WHERE series = "astc round 4"