The grounds of Sensoji Temple in Asakusa, Tokyo, are indeed open 24 hours a day, allowing visitors to walk through the iconic Kaminarimon Gate and along the Nakamise-dori shopping street at any time. However, the Main Hall (Hondo) and the official amulet shops have specific operating hours. Typically, the Main Hall is open from 6:00 AM to 5:00 PM from April through September, and from 6:30 AM to 5:00 PM from October through March. Visiting late at night is actually a highly recommended "insider" tip; while the shops will be closed, the temple buildings and the five-story pagoda are beautifully illuminated until 11:00 PM. This nighttime atmosphere is peaceful and far less crowded than the chaotic daytime hours. You can still offer a prayer at the front of the hall even after the doors are closed. So, while you can always access the site and take photos, you should plan to arrive before 5:00 PM if you wish to go inside the main sanctuary, buy a fortune (omikuji), or shop for traditional souvenirs.