In the Fief of Saeno ruled by a Matriarchy, a character must undergo a Trial by combat.
He has been framed by A magic item - sword, relic, wondrous item - and if found guilty of Terrorism, his punishment will be Imprisonment spell. According to the spell description, the creature is entombed in a state of suspended animation in a small sphere far beneath the surface of the ground. Cast Freedom to release the prisoner. Imprisonment and Freedom indicate you can reach the prisoner, so presumably you can choose the prisoner’s location. This is a perfect setup for dungeon design - put the prisoner at the heart of it.

Fief - Land or office granted to a vassal. Ownership is technically still with the granting lord, but revenue and production is given to the vassal. The lord technically retained the right to seize the land in case of disloyalty.
Matriarchy - Matriarchy is a term, which is applied to gynocentric form of society, in which the leading role is by the female and especially by the mothers of a community.
Trial by combat - Fight to the death, winner is innocent