The Parkour team represented by professional athletes from Urban Freeflow, will be showcasing their skills.
Parkour is normally done outdoors and consists of getting over all the obstacles in your path as you would do in an emergency.
Remember that amazing BBC One TV advert a few years ago, with a guy running over rooftops and jumping off things? That's Parkour!
There's also an eco-zone, skate ramp, live music, a surf movie playing in castle park as well as stalls and live music throughout the day.
As the sun goes down, the charity Baefest Ball kicks at Milkwood Jam in the city centre.
With a top line up of bands including The Mudskippers, Kalimist and Calico Street Riots, it's set to be an awesome night and there are some great prizes to be won in the raffle.