The Rock&Roll Marathon running along the Paseo de la Castellana.
Not only is the Rock&Roll Marathon the biggest running circuit in the world, but it also features live music on more than 20 stages, a festival at the finish line, a parallel 10-kilometre race and another half marathon that together turn Madrid into a sports extravaganza.
More info: EDP Rock´n´Roll Madrid Marathon & 1/2 2020 | Official tourism website (esmadrid.com)