The Tasitolu park was a sea of yellow and white umbrellas - the colours of the Holy See flag - as Timorese shielded themselves from the afternoon sun while awaiting Francis's arrival.
They received occasional spritzes of relief from water trucks that plied the field with water hoses in the 31C heat.
"Viva Papa Francisco," an announcer intoned as Francis arrived to cheers on Tuesday.
Tasitolu is said to have been a site where Indonesian troops disposed of bodies killed during their 24-year rule of East Timor.
The Catholic faithful were sprayed with water as they waited in the heat for mass with the Pope. (AP PHOTO)
Now it is known as the "Park of Peace" and features a statue of John Paul to commemorate his 1989 visit, when the Polish pope shamed Indonesia for its human rights abuses and encouraged the overwhelmingly Catholic Timorese faithful.
John Paul's visit helped draw attention to the plight of the Timorese people and the oppressiveness of Indonesia's rule, during which as many as 200,000 people were killed over a quarter-century.
Francis was celebrating mass at the same site on Tuesday, following in John Paul's footsteps to cheer on the nation two decades after it became independent in 2002.
East Timor remains one of the poorest countries, but the Timorese are deeply faithful - the territory has been overwhelmingly Catholic ever since Portuguese explorers first arrived in the early 1500s and some 97 per cent of the population today is Catholic.
They have turned out in droves to welcome the first pope to visit them as an independent nation.
Authorities said about 300,000 people had registered to attend the mass, but President Jose Ramos-Horta expected 700,000 and the Vatican predicted as many as 750,000.
The predicted numbers would approximate half East Timor's population of 1.3 million.
They lined up before dawn to enter the Tasitolu park, on the coast about 8km from downtown Dili.
"For us, the Pope is a reflection of the Lord Jesus, as a shepherd who wants to see his sheep, so we come to him with all our hearts as our worship," said Alfonso de Jesus, who came from Baucau, the country's second-largest city after Dili.
Young girls presented Pope Francis with a traditional shawl as he arrived at the Irmas Alma school. (AP PHOTO)
De Jesus, 56, was among the estimated 100,000 people who attended John Paul's 1989 mass, which made headlines around the world because of a riot that broke out just as it was ending.
John Paul looked on as baton-wielding Indonesian police clashed with some 20 young men who shouted "Viva a independencia" and "Viva el Papa!"
Francis has cheered East Timor for the progress it has achieved since independence and is seeking to encourage the country to strengthen its public institutions and look out for the poorest and most vulnerable.
Francis arrived in the country on Monday and on Tuesday morning visited a home for children with disability run by a congregation of religious sisters.
Young girls, including one without arms, presented Francis with a traditional shawl known as a tais as he arrived at the Irmas Alma school.
As he stroked the hand of a boy named Silvano in a stroller, Francis said taking care of children with such health needs "teaches us to care".
"As he allows himself to be cared for, we must learn to be cared for by God, who loves us," Francis said.
Francis then met clergy and religious sisters at the Cathedral of the Immaculate Conception, where he praised the women of the church and said their dignity must always be respected.