A plan to hold the finish of stage 20 of the 2025 Vuelta a España atop the Alto de Guarramillas - also known as the "Bola del Mundo" has come under fire from environmentalists who say the crowds, traffic, and infrastructure would damage the fragile high-mountain ecosystem.
The climb begins on the more widely used Puerto de Navacerrada before turning onto the final three-kilometre concrete track with gradients of 23%. First used in the Vuelta a España in 2010, and again in 2012, the finish takes place at a hiking area at 2,247 metres in altitude.
