Free weekly parkrun community 5k runs

parkrun organises free, timed 5k events every Saturday (and some juniors 2k events) in parks and open spaces across the UK; they are open to all abilities and ages (children typically need adult supervision or a guardian depending on local rules). To take part you must register once online for a free barcode, then turn up at any parkrun to run, walk or volunteer — there is no charge for participation and events are community-led.