The Orventis Arena was a location that existed on the planet Romulus and served as one of Ki Baratan's primary entertainment venues, capable of seating fifteen thousand beings.
In 2381, the Reunification Movement was legitimized by Praetor Tal'Aura, which allowed Spock to hold a public rally for peaceful dialogue at the Arena without repercussions from the Romulan Star Empire. (ST - Typhon Pact novel: Rough Beasts of Empire)
In 2383, Praetor Gell Kamemor met Spock at the Orventis Arena. (ST - Typhon Pact novel: Plagues of Night)