Matsumoto Castle, one of Japan's oldest castles, is famous for its unique black exterior. Located in Matsumoto City for over 400 years, it houses a remarkable collection of weapons and armor from the Warring States Period. Despite never witnessing battle, it's a must-visit in Nagano Prefecture, especially during twilight hours for a peaceful experience. The sight of swans on the moat against the castle and the blueish-purple horizon is unforgettable.