Spare set elements designed by George Tsypin for “La Clemenza di Tito” will connect the two Mozart operas thematically (Russell Thomas, who performed the title role of the Roman emperor, also returns as Idomeneus). Mr. Sellars noted the “primal and deeply earthed power” of the Felsenreitschule, a converted 17th-century riding school carved into the side of a mountain. “We don’t have to make a set for that.”

The opera’s culmination in a ballet sequence, to be choreographed by the Samoan-born Lemi Ponifasio, represents for Mr. Sellars “a gesture to stop talking, time for action.” One of two dancers is from the island nation of Kiribati, which is threatened by rising sea levels.

“[The people of] Pacific Island culture have profound rituals and mythologies for understanding their relationship to the ocean,” Mr. Sellars said. “These dancers will create a final ritual that restores the balances of the universe.”

The Felsenreitschule will also be home to a new production of Enescu’s “Oedipe,” staged by the veteran director Achim Freyer. The libretto follows the life of Oedipus from his birth and, in a twist of the original myth, a grove where he vanishes in a flash of flight. The score, meanwhile, is a unique blend of neo-classical elements, Eastern European folklore and French harmonies.

The conductor Ingo Metzmacher noted Enescu’s focus on the human dimension of the title character, who declares that he has “vanquished fate” in the final act. “Oedipus is not just a title character in the traditional sense,” he said by phone from Aix-en-Provence, France. “The other characters are marginal, exist around him.”

He also pointed to the skill with which Enescu reflects every nuance of the text, particularly in the third act, when the truth is revealed to Oedipus that he had murdered his father and married his mother. “The composer learned a lot from Sophocles,” he said. “The music is very gripping.”