Escape the city's hustle and bustle and step into Yoyogi Park, a sprawling green haven right next to Harajuku. Whether you're catching the stunning cherry blossoms in spring or the golden ginkgo leaves in autumn, the park offers a perfect slice of local life and a beautiful, calming retreat any time of year. Even though this is by no means a "hidden gem", it is surprisingly peaceful and quiet once you get off the main trail and wander off onto the smaller, greener paths that all interconnect with different sections of the park.
If possible, we'd also recommend visiting in the rain. It's very atmospheric and everything is so lush and green. There's also temples and shrines dotted around the park you can explore for free as well.