Research shows the positive impact of experiencing a restorative environment on the (mental) health and well-being of various users including children facing psychiatric issues. A museum park, where nature and art meet, provide such a restorative environment to its users. How the physical environment of a museum park, and opening the park towards a new user group such as these young visitors, plays a role in guards’ experience has hardly been studied. Based on focus group interviews with museum guards, complemented with insights from a more elaborate study involving patients and caregivers from a neighbouring child and adolescent psychiatric hospital, we aim to unravel how the physical environment of a museum park impacts on guards’ interactions with (young) visitors and art. We found that besides the benefits the museum park offers, its physical environment also confronts the guards with specific challenges, especially as regards balancing responsibilities, providing clarity, and allowing flexibility when it comes to interacting with (young) visitors. If a design does not support guards’ and caregivers’ feeling of control or clarity of expectations, this impacts on their behaviour towards the children and adolescents, and can even undermine a design solution that realises the outcomes of the co-creation process which aimed at improved well-being for the children and adolescents.