Agartha

alt=Refer to caption|upright=1.2|thumb|An illustration of Agartha within the hollow Earth, from Walter Siegmeister's 1960 book Agharta Agartha (variously spelled as Agharta, Aghartta, Agharti, among many other spellings) is a legendary kingdom said to be on the inner surface of the Earth. Though the story has many different versions, Agartha is usually said to be in Central Asia and led by a powerful figure sometimes called the King of the World, who secretly influences the surface. Later versions connect it to the belief in a hollow Earth. The idea of Agartha has been a popular subject in esotericism, occultism, and the New Age since the late 19th century.

The term and concept dates to the 1870s, first introduced by the French writer and colonial official Louis Jacolliot in his 1873 book ''''. Jacolliot said he had been given access to 15,000-year-old Indian manuscripts that told of the ancient city of Asgartha, its rise, and its fall. The original idea did not involve an underground kingdom, but was said to be India's destroyed former capital city, and is closer to Norse mythology than Indian mythology in content.