Marisquería El Cantábrico is a seafood restaurant in Madrid, Spain, and the useful context is what kind of evening it seems built to deliver. Readers should look for freshness, clean handling and the kitchen's confidence with the catch, because that is where a restaurant of this type earns its reputation. It is most compelling for diners seeking seafood-led cooking where freshness and restraint matter, especially if the night calls for something more considered than a safe default.