Booking Zhangjiajie National Forest Park through Trip.com was the smartest move of our trip. The multi-day pass (228 RMB) gave us 4 days of unlimited entry plus the free eco-shuttle buses, and the timed-entry slot system was clearly explained at checkout. Do not skip the advance booking — the park runs on strict real-name, timed reservations, and walk-ups are often turned away. Booking 3–7 days ahead on Trip.com gave us peace of mind and a smooth passport scan at the gate.