Fire Exit from hotel into residential gardens

Advice regarding signage and security. Our neighbour is a large busy hotel with a garden adjacent to ours. They have rights of easement with a fire exit through our housing block's private communal garden. There is an issue of hotel guests being curious and accessing our private garden. This puts residents security and privacy at risk. I've asked the hotel to display a sign that would say something like 'private property use only in case of fire'. What would be the correct signage. What security additions we could ask for. In the past we have requested an alarm but I don't think they want to pay for it.