Can you tell me more about the possibility of walking around Hydra? Is it a physical location, or are you referring to a digital platform or environment? If it's a physical island, what kind of infrastructure is in place to support visitors? Are there walking trails, sidewalks, or is it more of a rugged terrain? Are there any restrictions or permits required for visitors to roam freely? If it's a digital space, how do users navigate and explore it? Can you walk around virtually, or is it more of an interactive experience? Additionally, what kind of security measures are in place to ensure the safety of users, both physically and digitally?