A mystical tradition of the Kabbalists pertaining to the Throne Chariot of God which could ascend and descend through the different heavenly halls or palaces known as the Hekhaloth--with the seventh or final revealing the Glory of God.
Within the period of the Second Temple, Ezekiel's vision was interpreted as a mystical flight to heaven, and the Kabbalistic mystics established a technique of using a chariot for a meditation tool. Using the chariot the mystics would make an inward journey to the seven palaces while employing secret magic names to ensure their safe passage to and through each of the seven palaces in their correct order.
The mysteries, including both the procedures and formulae, surrounding these mystical journeys were known only to scholars of the Kabbalah until recently. Now, however, the important texts of the Greater Hekhaloth--the basic work of the Merkabah--have been published in English in an important work entitled Meditation and Kabbalah (1982) by Argeh Kaplan.