Nijo Castle, also known as Nijo-jo, is a UNESCO World Heritage Site located in Kyoto, Japan. The castle was built in 1603 as the residence of Tokugawa Ieyasu, the first shogun of the Edo Period, and was expanded in the 17th century by his grandson, Tokugawa Iemitsu.

Nijo Castle consists of two concentric rings of fortifications with a palace at the center. The inner circle is surrounded by walls and moats, while the outer circle has a garden and a series of gates and towers. The palace was designed to showcase the power and wealth of the Tokugawa shoguns, with lavish decorations, paintings, and carvings.

One of the most notable features of the palace is the "nightingale floors," which squeak when walked upon to alert the guards of any potential intruders. Other notable features include the "cherry blossom ceiling" in the reception hall, which is decorated with gold leaf and cherry blossom paintings, and the "emaki" (picture scroll) room, which features a series of hand-painted scenes from Japanese literature.

Nijo Castle is also famous for its beautiful gardens, which were designed by the renowned landscape architect, Kobori Enshu. The gardens include a pond, several waterfalls, and a variety of plants and trees, including cherry blossoms, maples, and pines.

Today, Nijo Castle is open to the public and is a popular tourist destination, attracting visitors from around the world who come to marvel at its architecture, art, and gardens.