Belgium is a country located in Western Europe and is divided into provinces. The four provinces mentioned in the crossword are Antwerp, LIEGE, Yser, and Ostend. Antwerp is a province located in the northern part of Belgium and is the most populous province with a population of over 1.5 million people. LIEGE is a province located in the east of Belgium and is known for its industrial heritage. Yser is a province located in the west of Belgium and is known for its flat landscape. Ostend is a province located in the northwest of Belgium and is known for its beaches and coastal resorts.