Mayan and Aztecs also believed in a underworld. This underworld was called Xibalba. Xibalba was where the evil gods lived. Xibalba was ruled by Mictlantecuhtli. According to the Aztecs and Mayans, almost all the population ended up in Xibalba when they died. They had to go through all Xibalba to finally get to heaven. Xibalba had nine lives that they people had to pass through. This rarely happened.
As stated in The Mythology of Aztec and Maya by Charles Phillips, "...most souls were destined for the underworld...". The underworld was a place of mischief and misfortune. A place of misery and hopelessness. It was not a happy place to be. Xibalba was said to be the realm of dogs. This is why when an owner dies they often would sacrifice their dog over them to help them get to their afterlife.