Religious literature is filled with descents into the underworld. IF you want to see some of the entrances click on the link.
Both Enkidu and Gilgamesh go down to the underworld in the Epic.
Innana's reasons for going to the Babylonian underworld are unclear, but give rise to the legendary "Dance of the Seven Veils" as she strips off her clothes to pay the gate keepers.
Orpheus descends into the underworld for Eurydice.
Odysseus, born centuries before Google, has to go to the underworld to get the answers he seeks.
Osiris, of course,Heracles to rescue Thesues' own ill advised expedition, Hermes, Dionysus, Odin, Baldur, Pwyll, and even King Arthur get in on the act.
Japan has Izanagi and Izanami in Yomi, the Mayans had the Hero Twins Hunahpu and Xbalanque, and for the Ohlone Kaknu fights Body of Stone - a kind of underworld god who held the bodies of many of the People.
Most interesting, to me at least, is the so called "Harrowing of Hell" in some Christian traditions. Typically based on 1 Peter 3:19-20 "went and made proclamation to the imprisoned spirits—to those who were disobedient long ago when God waited patiently in the days of Noah while the ark was being built. In it only a few people, eight in all, were saved through water...." It is also one of the more troubling parts of the Apostles' Creed - "he descended into Hades/Hell..." The story seems to have originally been collected in a non-canonical book called the Gospel of Nicodemus aka The Acts of Pilate. Since the book is seen to be made of older sources its exact origin is unclear. The Apostles' Creed dates from 390 CE, and the Gospel of Nicodemus would be contemporary with that period.
The tradition states that Jesus in spiritual form went to the underworld between his crucifixion and Resurrection to..do something. Depends on who you ask.
Catholics teach that Jesus went to get the righteous dead who awaited in "the bosom of Abraham" to take them to Heaven. In the Eastern Orthodox Church, the Harrowing of Hades is celebrated annually on Holy and Great Saturday, during the Vesperal Divine Liturgy of Saint Basil. At the beginning of the service, the hangings in the church and the vestments worn by the clergy are all somber Lenten colors (usually purple or black). Then, just before the Gospel reading, the liturgical colors are changed white and the deacon performs a censing, and the priest strews laurel leaves around the church, symbolizing the broken gates of hell; this is done in celebration of the harrowing of Hades then taking place, and in anticipation of Christ's imminent resurrection. A famous icon depicts Jesus with Adam and Eve by the wrists, dragging them up out of Sheol, the grave or underworld. An early Lutheran confession says "we believe simply that the entire person, God and human being, descended to Hell after his burial, conquered the devil, destroyed the power of Hell, and took from the devil all his power." John Calvin said taht many believers "have never earnestly considered what it is or means that we have been redeemed from God's judgment. Yet this is our wisdom: duly to feel how much our salvation cost the Son of God." He went further to say "Christ's descent into Hell was necessary for Christians' atonement, because Christ did in fact endure the penalty for the sins of the redeemed." According to the LDS (Mormons)"The Lord went not in person among the wicked and the disobedient who had rejected the truth, to teach them; but behold, from among the righteous, he organized his forces…and commissioned them to go forth and carry the light of the gospel to them that were in darkness, even to all the spirits of men; and thus was the gospel preached to the dead ... to those who had died in their sins, without a knowledge of the truth, or in transgression, having rejected the prophets." This belief leads to their practice of Baptism for the Dead, since the spirits of the dead may yet still hear the Gospel and repent.
Many Christian theologians, however, have rejected the idea of the Harrowing of Hell. Augustine said it was metaphor while modern writers like John Piper and Wayne Gruden deny it altogether.
This is what a 17th century artist thought it might look like.