Heaven, or the heavens, is a common religious, cosmological, or transcendent place where beings such as gods, angels, spirits, saints, or venerated ancestors are said to originate, be enthroned, or live. According to the beliefs of some religions, heavenly beings can descend to earth or incarnate, and earthly beings can ascend to heaven in the afterlife, or in exceptional cases enter heaven alive. Heaven is often described as a 'higher place', the holiest place, a Paradise, in contrast to hell or the Underworld or the 'low places', and universally or conditionally accessible by earthly beings according to various standards of divinity, goodness, piety, faith, or other virtues or right beliefs or simply the will of God. Some believe in the possibility of a heaven on Earth in a world to come. Another belief is in an axis mundi or world tree which connects the heavens, the terrestrial world, and the underworld. In Indian religions, heaven is considered as Svarga loka, and the soul is again subjected to rebirth in different living forms according to its karma. This cycle can be broken after a soul achieves Moksha or Nirvana. Any place of existence, either of humans, souls or deities, outside the tangible world (heaven, hell, or other) is referred to as otherworld. The modern English word heaven is derived from the earlier (Middle English) heven (attested 1159); this in turn was developed from the previous Old English form heofon. By about 1000, heofon was being used in reference to the Christianized 'place where God dwells', but originally, it had signified 'sky, firmament' (e.g. in Beowulf, c. 725). The English term has cognates in the other Germanic languages: Old Saxon heƀan 'sky, heaven' (hence also Middle Low German heven 'sky'), Old Icelandic himinn, Gothic himins; and those with a variant final -l: Old Frisian himel, himul 'sky, heaven', Old Saxon and Old High German himil, Old Saxon and Middle Low German hemmel, Old Dutch and Dutch hemel, and modern German Himmel. All of these have been derived from a reconstructed Proto-Germanic form *hemina-. or *hemō. The further derivation of this form is uncertain. A connection to Proto-Indo-European *ḱem- 'cover, shroud', via a reconstructed *k̑emen- or *k̑ōmen- 'stone, heaven', has been proposed. Others endorse the derivation from a Proto-Indo-European root *h₂éḱmō 'stone' and, possibly, 'heavenly vault' at the origin of this word, which then would have as cognates Ancient Greek ἄκμων (ákmōn 'anvil, pestle; meteorite'), Persian آسمان (âsemân, âsmân 'stone, sling-stone; sky, heaven') and Sanskrit अश्मन् (aśman 'stone, rock, sling-stone; thunderbolt; the firmament'). In the latter case English hammer would be another cognate to the word. The ancient Mesopotamians regarded the sky as a series of domes (usually three, but sometimes seven) covering the flat earth. Each dome was made of a different kind of precious stone. The lowest dome of heaven was made of jasper and was the home of the stars. The middle dome of heaven was made of saggilmut stone and was the abode of the Igigi. The highest and outermost dome of heaven was made of luludānītu stone and was personified as An, the god of the sky. The celestial bodies were equated with specific deities as well. The planet Venus was believed to be Inanna, the goddess of love, sex, and war. The sun was her brother Utu, the god of justice, and the moon was their father Nanna. In ancient Near Eastern cultures in general and in Mesopotamia in particular, humans had little to no access to the divine realm. Heaven and earth were separated by their very nature; humans could see and be affected by elements of the lower heaven, such as stars and storms, but ordinary mortals could not go to heaven because it was the abode of the gods alone. In the Epic of Gilgamesh, Gilgamesh says to Enkidu, 'Who can go up to heaven, my friend? Only the gods dwell with Shamash forever.' Instead, after a person died, his or her soul went to Kur (later known as Irkalla), a dark shadowy underworld, located deep below the surface of the earth. All souls went to the same afterlife, and a person's actions during life had no impact on how he would be treated in the world to come. Nonetheless, funerary evidence indicates that some people believed that Inanna had the power to bestow special favors upon her devotees in the afterlife. Despite the separation between heaven and earth, humans sought access to the gods through oracles and omens. The gods were believed to live in heaven, but also in their temples, which were seen as the channels of communication between earth and heaven, which allowed mortal access to the gods. The Ekur temple in Nippur was known as the 'Dur-an-ki', the 'mooring-rope' of heaven and earth. It was widely thought to have been built and established by Enlil himself.