The United States district courts are the general trial courts of the United States federal court system. Both civil and criminal cases are filed in district courts, which are courts of law, equity, and admiralty. There is a United States bankruptcy court associated with each United States district court. Each federal judicial district has at least one courthouse, and many districts have multiple. Most decisions of district courts may be appealed to the respective court of appeals of their circuit, with a small number instead being appealable to the Federal Circuit, or directly to the Supreme Court.