A children's play yard comprising: a play yard frame (100, 500) comprising: one or more lower horizontal frame members (104, 504); one or more vertical frame members (106, 506) attached to said lower horizontal frame members (104, 504), wherein at least a portion of said vertical frame members (106, 506) extends upwardly from said lower horizontal frame members (104, 504); and one or more movable retention members (108, 608) operatively connected to said vertical frame members (106, 506) and configured to move between an inward receiving orientation and a retaining orientation; wherein said moveable retention members (108, 608) include a lower end pivotally connected to one of said vertical frame members (106, 506) in order to permit said moveable retention members (108, 608) to pivot between said inward receiving orientation and said retaining orientation; and a removable play yard liner comprising: one or more sidewalls; and one or more engagement features configured to engage said one or more moveable retention members (108, 608); wherein said sidewalls of said play yard liner extend between said moveable retention members (108, 608) of said play yard frame (100, 500) and define a bounded area within said play yard when said engagement features are engaged with said retention members (108, 608) and said retention members (108, 608) are positioned in said retaining orientation. a play yard frame (100, 500) comprising: one or more lower horizontal frame members (104, 504); one or more vertical frame members (106, 506) attached to said lower horizontal frame members (104, 504), wherein at least a portion of said vertical frame members (106, 506) extends upwardly from said lower horizontal frame members (104, 504); and one or more movable retention members (108, 608) operatively connected to said vertical frame members (106, 506) and configured to move between an inward receiving orientation and a retaining orientation; wherein said moveable retention members (108, 608) include a lower end pivotally connected to one of said vertical frame members (106, 506) in order to permit said moveable retention members (108, 608) to pivot between said inward receiving orientation and said retaining orientation; and a removable play yard liner comprising: one or more sidewalls; and one or more engagement features configured to engage said one or more moveable retention members (108, 608); one or more lower horizontal frame members (104, 504); one or more vertical frame members (106, 506) attached to said lower horizontal frame members (104, 504), wherein at least a portion of said vertical frame members (106, 506) extends upwardly from said lower horizontal frame members (104, 504); and one or more movable retention members (108, 608) operatively connected to said vertical frame members (106, 506) and configured to move between an inward receiving orientation and a retaining orientation; wherein said moveable retention members (108, 608) include a lower end pivotally connected to one of said vertical frame members (106, 506) in order to permit said moveable retention members (108, 608) to pivot between said inward receiving orientation and said retaining orientation; and a removable play yard liner comprising: one or more sidewalls; and one or more engagement features configured to engage said one or more moveable retention members (108, 608); wherein said sidewalls of said play yard liner extend between said moveable retention members (108, 608) of said play yard frame (100, 500) and define a bounded area within said play yard when said engagement features are engaged with said retention members (108, 608) and said retention members (108, 608) are positioned in said retaining orientation.