Germany and Argentina will contest the 2014 Fifa World Cup final on Sunday in front of an expected television audience of more than a billion.
Germany would be the first European team to win the tournament in South America if they take the title for the first time since 1990.
If Argentina triumph it would end a 28-year wait for World Cup glory since they beat West Germany in 1986.
The game, a 20:00 BST kick-off at Rio's Maracana, is a 79,000 sellout.
There will be live uninterrupted coverage on BBC One and the BBC Sport website from 19:00 BST, while there is also live commentary on BBC Radio 5 live.
Germany, seeking a fourth World Cup,crushed hosts Brazil 7-1 in the semi-finals, while two-time winners Argentina beat Netherlands 4-2 on penalties after a 0-0 draw.
Rio is preparing what local authorities claim to be the "largest security operation in the city's history", with more than 25,000 people involved, including local agents, military police, civil police, firefighters, the armed forces and intelligence agents.
The authorities say terrorism, clashes between fans, the presence of at least 15 members of foreign governments and the security of Brazil President Dilma Rousseff are the main areas of concern.
Argentina goalkeeper Sergio Romero, who has not conceded a goal in the knockout phase and was the hero of the win against Netherlands, said: "The most important thing is that our team and our country provide the best image in the eyes of the world, that the world will speak well of Argentina.
"We will remember what the champions of 1978 and 1986 achieved but we will also try to achieve glory by the fight and heart of this team. Maybe for many people it is not the dream final because they wanted to play Brazil, but it will be a fantastic game."
Germany midfielder Bastian Schweinsteiger said: "There is huge anticipation here and in Germany. We have no pressure. We know how to handle things. We just have to concentrate on our jobs and what makes us strong. We have to be calm and have clear heads focused on the football."
The Germans will be playing in their eighth World Cup final, more than any other nation, but have won only one of their past four finals.
Sunday's game is the climax of a World Cup that is being regarded as a huge success in Brazil, with fears of widespread public protests similar to those that marred last summer's Confederations Cup proving unfounded.
According to local sources, 692,000 tourists from 203 countries have entered Brazil during the month in which the World Cup has been staged.
Brazil's hopes of winning the World Cup for the first time since 2002, when they beat Germany in Japan, were wrecked by those same opponents - but supporters still packed the Fanfest on Copacabana beach on Saturday to watch the hosts' 3-0 defeat by Netherlands in the third-place play-off.
Argentina fans were also flooding the area ahead of Sunday's final, hoping their team can win the World Cup deep in the heart of sporting enemy territory in the iconic surroundings of the Maracana.
The tournament has been notable for its attacking football, and if the final features two goals, this will be the highest-scoring World Cup, beating the 171 goals in 1998.
But there has been controversy, too, with Uruguay striker Luis Suarezbanned from all football-related activity for four months for biting Italy defender Giorgio Chiellini during a group game.