Pope Leo XIV blesses world's tallest church in Barcelona

Pope Leo XIV blesses the world's tallest church, inaugurating the Sagarda Familia final sandcastle spire in Barcelona as he continues his tour in Spain.

Droves of faithfuls made their way to the Mass, which coincides with the centenary of Antoni Gaudi's architectural masterpiece.

An estimated 120,000 people line the streets around Sagrada Familia Basilica as Pope Leo XIV makes his way to a mass and a blessing.

The service marks the centenary of the death of architect Antoni Gaudi and celebrates the inauguration of the chruch's final soaring sandcastle spire.

Inside the church, Leo, speaking in Catalan and Spanish, calls the temple one of the world's most visited monuments and a symbol of unity and harmony for all of Spain.

He likens the ongoing building project to the lifelong journey all Christians make to find God.

With Spanish King Felipe VI and Queen Letizia sitting by his side, a hundreds-strong choir fills the basilica with song.

Afterwards, the American pontiff blesses the basilica's Tower of Jesus Christ and its ceramic cross from outside.

A spectacular light show illuminates the basilica's stained glass windows from the inside as fireworks shoot off its facade to the soundtrack of another choir performance.

The Sagrada Familia was finally completed last year after a century of construction, and at 172.5 metres, its the world's tallest church.

The visit to the sacred monument marks the highlight of Leo's weeklong visit to Spain, the first by a pope in 15 years to the once staunchly Catholic European country, which has experienced secularising trends in recent years.

Leo's next stop is the Canary Islands.