A modular barrier system enables demountable outdoor rinks—typically for ice hockey, or ice skating, or street hockey. A rink includes multiple panels, each having a factory-attached link. These panels are linearly disposed, adjacent to one another, to form a piecewise continuous boundary wall enclosing a desired area. Attaching one link to the next, typically via insertion of a thumbscrew, connects the panels into a robust assembly. Both straight and curved panels are provided, thereby enabling a rink with round corners. Each panel includes a shell molded from plastic resin, and has a hollow interior which can be filled with water (or other ballast).