boundary

Line around the edge of an area; a perimeter. The boundary of a circle is known as the circumference. The boundary which marks the limit of land may be indicated by a post, ditch, hedge, march of stones, road, or river, or it may be indicated by reference to a plan, or to possession of tenants, or by actual measurement.

When two properties are divided by a road or river, the middle line of the road or river is regarded as the boundary between the owners (usque ad medium fili); whereas a hedge or fence is taken to belong equally to the adjoining owners.

The boundaries of towns and parishes depend upon ancient charter or custom. Local government boundaries are laid down initially by act of Parliament, but are subject to revision by permanent and separate local government boundary commissions for England and Wales. The reports of these commissions are advisory and are implemented by Parliament in legislation introduced by the secretary of state for the Environment. The boundaries of parliamentary constituencies are subject to review by separate boundary commissioners for England, Wales, Scotland, and Northern Ireland, which report to the home secretary, who presents their reports to Parliament.