Complex sentence: Widely acknowledged to be the premiere event, the Guinness World Oyster Opening Championship is held in September at the Galway Oyster Festival, as well as the annual Clarenbridge Oyster Festival'Oyster Opening Competition' both held in Galway, Ireland.
Split into simpler sentences: Widely acknowledged to be the premiere event, the Guinness World Oyster Opening Championship is held in September at the Galway Oyster Festival. The annual Clarenbridge Oyster Festival'Oyster Opening Competition' is also held in Galway, Ireland.