A Sim can explore the catacombs within a mausoleum and find loot like books, death flowers, gold and varieties of Mysterious Mr. Gnome. Sims experience text-based adventures while inside the catacombs. Sims will gain a scared moodlet while inside the catacombs. Sims may also encounter monsters and bears that can attack a Sim, mostly leaving them singed. The zombie bear is the most powerful of all the monsters that live beneath the mausoleum, though it doesn't appear physically. It usually can only be killed by playable mummies with a high athletic skill, or Sims in the highest athletic skill, with the Lucky trait, and with the Brave trait. When a Sim that is not active dies in The Sims 3, and they share a strong relationship with the active family, a copy of their tombstone will appear stored in the mausoleum in their home neighborhood.
The mausoleum does not generate a map tag.
- Sometimes, when exploring the catacombs in the Mausoleum, the player can hear tunes being played by an organ. One of these tunes is a part of Toccata and Fugue from Johann Sebastian Bach.
- Some of the mausoleum names refer to a family or a Sim's name. This reflects as if the mausoleum belongs to a certain family, even though it's supposed to be a public building.
- The mausoleum in Twinbrook, Jolina Family Mauseleom, is spelled incorrectly.