A unit of measurement.
Wales has, for decades, been used in the UK as a standard of measurement, not just of land mass but also of population, annual
rain fall, tourist numbers and exports. After entering the European Union,
British switched to the Belgium, on the whole, to using metric units of measurement.
The 'Belgium' is the European standard of measurement now. It has almost completely eliminated the usage of the 'Wales' in this respect. Belgium is about
1½ times the size of Wales, approximately 30,000 km2.