Few parties are as massive, anticipated and colourful as Brazil's Carnival, a weeklong celebration that paralyses everything else in South America's biggest nation.

Tens of millions of people dress up to go onto the streets to take part in "blocos", or parades led by a samba band.

They go on all day and night, with every neighbourhood hosting at least one.

Some are small, while others - like the Banda da Ipanema or Gay Bloco - are enormous and attract hundreds of thousands of people of all ages.

But without a doubt the best known part of Carnival is the two-day parade at the famous Sambadrome in Rio de Janeiro, where the city's 12 best samba schools compete for the prestigious honour of being selected the year's winner.

The samba schools, which come from working-class Rio neighbourhoods, spend millions of dollars to build enormous floats and lavish costumes used by up to 2,000 participants.

They dance and sing past the judges during their performances that last up to 80 minutes. Each school has a theme.

This year's included the 450th anniversary of Rio de Janiero, The African Roots of Brazil, the Women of Mangueira (one of the schools), and "What would you do if tomorrow were the last day of your life?"

The best known part of Carnival is the two-day parade at the famous Sambadrome in Rio de Janeiro [Lucia Newman/Al Jazeera]

 

Participants dance and sing past the judges during their performances that last up to 80 minutes [Lucia Newman/Al Jazeera]

 

Samba schools spend millions of dollars to build enormous floats and lavish costumes used by up to 2,000 participants. [Lucia Newman/Al Jazeera]

 

Sunny disposition for bloco in Flamengo, Rio de Janeiro [Lucia Newman/Al Jazeera]

 

Tens of thousands jam park and bridges of Flamengo for Orquestra Voadora bloco [Lucia Newman/Al Jazeera]

 

A couple dress up for bloco in Flamengo [Lucia Newman/Al Jazeera]

 

Source: Al Jazeera