Vuelta a España organisers have banned fans from several of the major climbs during this year's race as part of attempts to protect riders from coronavirus.
Organisers Unipublic said it was introducing a series of restrictions to some stage departures, finishes and mountain passes.
This followed talks with health authorities and the Government delegations of all territories featured on the route of the race.
The latest restrictions come a week after the Basque Government and Unipublic decided that the climbs to the Arrate and Orduña mountain passes, due to feature on stages one and seven, would take place without spectators.
Fans will now be banned from the Laguna Negra climb on stage three, as well as the summit finish on the Col du Tourmalet on stage six.
Spectators will also be prohibited from watching riders on the Puerto de Orduña, a climb which will be covered twice on stage eight.
Summit finishes at Alto de Moncalvillo and Alto de la Farrapona on stage eight and 11 have been included in the restrictions, along with Alto de L'Angliru on stage 12.
The final restrictions currently relate to the finishes at Mirador de Ezaro on stage 13 and Alto de la Covatilla on stage 17.
"La Vuelta deeply regrets that the current epidemiological situation in Spain does not allow the adequate conditions required for the public to be present at those points," a Unipublic statement read.
"The race will take place without its usual commercial and advertising activities, such as the Parque Vuelta and the advertising caravan, in order to avoid any unnecessary crowds.
"The organisation will also rigorously enforce a maximum capacity control in all restricted race areas.
"The team parking area, a space that is usually open to the public in order to allow fans to get closer to the riders, will be completely closed off to the public in order to guarantee the protection of the athletes and of the personnel working with their respective teams.
"These restrictions, already important today, may be modified in accordance with the evolution of the situation over the coming days."
Organisers have said a reduced group of personnel, media, sponsors, teams and state security forces at the race will be subject to strict sanitary protocols.
They are hoping to encourage fans to stay away from the race and are using social media channels to urge people to enjoy the Grand Tour from home.
Unipublic say the objective is to avoid any type of crowd surrounding the event, by respecting the criteria established by the national and autonomous health authorities.
This year's Vuelta is scheduled to run from October 20 to November 8.
The first five days overlap with the end of the Giro d'Italia, another of the three Grand Tours alongside the Tour de France.
The Vuelta was due to begin in The Netherlands, but the first three stages of the race were instead axed because of the coronavirus pandemic.
This left the Grand Tour consisting of 18 stages this year, with organisers also forced to modify stages 15 and 16 which initially were intended to take place in Portugal.
Spain has faced a rise in coronavirus cases in recent weeks, with the country's Government seeking to impose an emergency lockdown in the capital Madrid.
The Vuelta a España is due to be the final of cycling's Grand Tours to begin this year.
The Tour de France was successfully completed in September after the event was rescheduled, while the Giro d'Italia is ongoing.
The Giro has seen the withdrawal of two teams following positive coronavirus cases, prompting questions over whether the race will be able to conclude as planned.