Since there's not a whole lot happening immediately around the venue, you're probably gonna head back into town afterwards (on the L3 bus, perhaps?) and once there, you could benefit from paying a visit to the Cathedral of Santa Maria. It is a stunning piece of architecture (with gorgeous surroundings, in the form of other buildings and grassy areas) which embodies the whole atmosphere of Vitoria: it is old and full of history, but still thriving.

The sports complex is quite far from the city centre, so you might take public transport to go there. Vitoria is not very big, but it's a picturesque city. Plaza de la Virgen Blanca is the main square in the city and you will see lots of people and bar for "pintxos” around here. Just take any small street and start walking. I like the atmosphere in these quiet streets. If you are hungry, go to La Malquerida (Correría Kalea, 10). I was eating twice there during my weekend trip!