Professor: Today we're discussing the impact of urban green spaces on mental health. A recent study in Melbourne followed 1,000 residents over five years. Interestingly, those living within 300 meters of a park reported 20% lower stress levels. However, the effect was stronger for people over 50, and surprisingly, the size of the park mattered less than its accessibility. Also, participants who visited green spaces at least once a week showed better sleep quality, but only if the visit lasted more than 30 minutes. So, it's not just having nature nearby, but how you use it.