The two million revelers who ushered in 2016 on Rio de Janeiro's famed Copacabana Beach left behind a calling card Friday: 315 tonnes of trash for the Olympic host city to cart away.

An army of nearly 1,200 workers and a fleet of 250 trash trucks began working at dawn to haul away the mountain of refuse strewn over six kilometers (four miles) of beach.

In some instances, workers had to carry on their clean-up duties while weaving between exhausted New Year's party-goers who stayed on the beach catching up on their sleep long after most of the merry-makers had gone home.

Within about four hours of starting their labors, the beach was restored to its mostly pristine state, and was ready to welcome a new round of visitors on what looked to be scorching beach weather to start the New Year: sunny and about 40 degrees Celsius (104 Fahrenheit).

New Year's Eve festivities in Brazil's biggest party town included more than 30,000 fireworks launched from 11 barges anchored off its tropical coastline.

Even with the Friday cleanup, Rio's legendary New Year's celebrations are a cash cow for the city, and were expected to bring more than $680 million to the local economy this year, the best in five years.

The massive cleanup operation also was good practice for this summer's Olympic Games, when throngs of visitors will swarm the city, including its iconic beaches.