Arguably one of the most unusual public parks in Tokyo, Tetsugakudō Park in Nakano Ward was established by philosopher and occult expert Inoue Enryō, who was also the founder of the Toyo University.

In 1904, Inoue had a small temple built, dedicated it to Socrates, Immanuel Kant, Confucius, and the Buddha, and dubbed it Tetsugakudō or the Philosophy Pavilion. Later, between 1909 and 1912, he founded more structures around the temple, creating what would be known as Tetsugakudō Park.

The park consists of 77 structures based on Inoue's unique worldview, dedicated to an eclectic mix of philosophical ideas and esoteric teachings. Some buildings simply exist to represent the concept of space and time, while some are their own shrines to philosophers of old, such as the Yellow Emperor of China, Thales of Miletus, and Akshapada Gautama.

Inoue was also a critical researcher of the yōkai, colloquially known as the Yōkai Professor, approaching paranormal phenomena and superstitions from a scientific aspect. It is also believed that the modern use of the word yōkai, as a collective reference to supernatural creatures and ghosts, was popularized by Inoue in his process to demystify folklore.

The main entrance to the park, named Tetsuri-mon, gives a fascinating glimpse at Inoue's view on the supernatural. Flanking the gate is a pair of painted statues, one of the tengu and another of a ghost, representing the material and the immaterial, respectively.

In 1944, following the death of Inoue, the park was donated to the municipality of Tokyo, and then to Nakano Ward in 1975. It is now nationally designated as a Place of Scenic Beauty.

In 2009, in commemorations of the 140th anniversary of the two nations' relations, a replica of the Garden of Philosophers in Budapest was given to the park by Hungary. This installation includes statues of such historical figures as Jesus Christ, Bodhidharma, Akhenaten, Hammurabi, Justinian, Francis of Assisi, and Prince Shōtoku.