Italy has decided to implement a new coronavirus certification to rein in a summer surge in infections amid the fight against COVID-19.

The certification – the so-called "Green Pass" – has already started to be necessary to enter gyms, theaters, indoor pools and the inside areas of restaurants, bars and cafes as of Friday. Therefore, Pompeii's archaeological park is offering free swab tests now, the Vatican Museums posted refund instructions and tourists whipped out smartphones to show QR codes along with admission tickets.

To obtain a certificate, individuals must show they have received at least one dose of a coronavirus vaccine approved for use in the European Union, recovered from COVID-19 in the past six months or have negative lab results from a test done within the previous 48 hours. The government announced the rule on July 22, giving residents and tourists two weeks to prepare. Some 50 million of Italy's 60 million residents had downloaded the certification by late July.

Along the sidewalk flanking Vatican City's walls, visitors to the Vatican Museums, one of the world's most popular attractions, got ready to show their cellphones to workers at the entrance.

"No problem. You have your certificate on your phone.," Ivan Wolska, a tourist from Poland, said. Wolska expected to encounter delays, but instead "it was so fast."

Visitors from France found the new Italian system familiar. Their country has already introduced entrance requirements even tougher than Italy’s since they also apply to outdoor dining. "It is good for everybody’s safety. It is positive for the economy, too,'' French tourist Alexine Prentignac said.

While many find it convenient to flash their Green Pass on a phone, paper certification is also acceptable in Italy. The Vatican Museums website cautioned visitors to have an identity document handy so staff could "verify actual ownership" of the Green Pass. For anyone unwilling or unable to comply, the website offered instructions on how to request a ticket refund.

At Pompeii, one of Italy's most-visited tourist sites, officials teamed up with the city of Naples to offer coronavirus tests during the opening hours of the sprawling park featuring the ancient Roman city's ruins. For now, the tests are being given on an experimental basis, free of charge.