-- Database schema
| product : product_id [ INT ] primary_key , product [ TEXT ] , dimensions [ TEXT ] , dpi [ INT ] , pages_per_minute_color [ INT ] , max_page_size [ TEXT ] , interface [ TEXT ] | store : Store_ID [ INT ] primary_key , Store_Name [ TEXT ] , Type [ TEXT ] , Area_size [ INT ] , Number_of_product_category [ INT ] , Ranking [ INT ] | district : District_ID [ INT ] primary_key , District_name [ TEXT ] , Headquartered_City [ TEXT ] , City_Population [ INT ] , City_Area [ INT ] | store_product : Store_ID [ INT ] primary_key store_product.Store_ID = store.Store_ID , Product_ID [ INT ] | store_district : Store_ID [ INT ] primary_key store_district.Store_ID = store.Store_ID , District_ID [ INT ] store_district.District_ID = district.District_ID |
-- -- What is the name of the district with the smallest area?

SELECT district_name FROM district ORDER BY city_area ASC LIMIT 1;