People gather in front of Teatro Colon in Buenos Aires on Monday as the opera house reopened.People gather in front of Teatro Colon in Buenos Aires on Monday as the opera house reopened. (Natacha Pisarenko/Associated Press)

Buenos Aires' Teatro Colon, one of the world's great opera houses, reopened its doors on Monday as part of Argentina's bicentenary celebrations.

Thousands of people gathered in front of the building, where the second act of Puccini's La Bohème and excerpts from Tchaikovsky's ballet Swan Lake were broadcast on a large screen, while 2,700 guests viewed the performances inside.

The opera house had been closed for nearly four years for renovations.

The makeover cost about $100 million and ran two years over schedule. It included restoring the exterior, replacing some of the original flooring and chandeliers, and installing a natural air conditioning system.

Modelled on La Scala in Milan, the Argentine venue where Luciano Pavarotti, Placido Domingo and Enrico Caruso loved to sing was inaugurated in 1908 after 20 years of construction and is renowned for its natural acoustics.

More than 1,000 artisans restored the French stained glass and other historic features.

Teatro Colon is a stage to both opera and ballet.

With files from The Associated Press