From the previous day's finish in Iscar, the route continues south to the gates of Madrid. There are just over 20 kilometres on the map between the start in Manzanares El Real and the finish in Guadarrama - both small towns are stage towns in the Tour of Spain for the first time. At the end of the day, however, the 208-kilometre stage is the longest of the 2023 Vuelta.
This is made possible by several loops that the peloton has to complete. In contrast to the 19th stage, on which there was hardly any elevation, the profile of the penultimate stage shows hardly a flat kilometre. Ten mountain classifications, all in the 3rd category, have to be mastered in total. The first summit after twelve kilometres, the last one twelve kilometres before the end. In between, it's all up and down.
While the first and last climbs are only ridden once each, the peloton crosses the four climbs in between twice. They are on a 35 kilometre loop that has to be ridden twice. In addition, there are two extra detours and a few kilometres on the route that were already ridden in the opposite direction at the start of the day, as the finish will be reached for the first time after just 22 kilometres.
Each mountain in itself is not really a problem for the peloton. In total, however, there are more than 4000 metres in altitude. As there are constant ups and downs and the whole thing happens on predominantly narrow and winding roads, there are hardly any recovery phases and stress is inevitable.
However, if there are no longer a few seconds at stake in the overall classification, the battle for the mountain jersey is likely to take centre stage. A rider can still collect a maximum of 30 points for the classification. An early breakaway group with a few mountain goats will break away early and also have a good chance of fighting for the stage win.
At least if the overall standings are already clear. If not, there are two races in the race. The GC favourites, who otherwise prefer to stay out of the fray and play it safe in difficult road conditions to avoid crashes, join in the fight for the day's victory - and more - because there are valuable bonus seconds at the finish and on the last climb.
The peloton sets off at 11:55 for the first neutralised kilometres, with a sharp start just seven minutes later. With calculated speeds of between 36 and 40 km/h, the riders can expect to arrive in Guadarrama between 17:13 and 17:48.
Eurosport will broadcast all stages of the Vuelta a Espana 2023. The 20th stage will be shown free-to-air on Eurosport 1 from 11.30am. Including post-stage coverage, the broadcast will run until 18:00. The paid providers GCN+ and Discovery+ will also be showing a live stream on the internet.