The Bairiki National Stadium is the principal sports venue of Kiribati, used for football internationals, athletics meets, and the major national events. It is a small open ground with a single low stand, which fits the country: Kiribati is one of the smallest national football associations in the world and matches against visiting teams from elsewhere in the Pacific draw most of South Tarawa.
For travellers it is worth a stop more for atmosphere than spectacle. If there is no match on, you can wander in, watch local kids playing pickup games, and get a feel for the everyday Bairiki government district that surrounds it.