The 4,000-square meter stage accommodated 2,200 people. This is one of the largest platforms ever built for this type of function, and was the site of events on 20 and 21 August. His Holiness the Pope, the Royal Family, members of the Catholic Church and other authorities and guests were seated in different areas of the platform. The podium from which the Pope spoke was 3.20 metres above ground level.

The altar was 190 metres long, 21 metres high and 36 metres wide. The construction of such a large structure required a 21,000-cubic metre scaffolding as well as 500 tonnes of concrete ballast to offset potential winds and as a safety measure.

The structure was shaped like a wave or mountain. More than 9,000 square metres of textured surface area was painted white to resemble an iceberg.

A 15-tonne, 264-square metre tree-like structure was installed in the centre of the platform to provide shade for His Holiness and the Royal Family.

A moving platform was used during the Mass on Saturday, 20 August to raise the Toledo Monstrance, which weighs over 200 kilos.

The altar also included separate areas for participants, including sacristies, changing rooms, restrooms, first aid, etc. Construction required 1,300 square meters of plasterboard.

FCC and OHL are among the large Spanish companies that contributed to World Youth Day, held in Madrid last week and whose main events were presided over by Pope Benedict XVI. The highlight of the event was the Mass held at the Cuatro Vientos aerodrome on Sunday, 21 August. The day before, the Pope officiated a Vigil there. From the stage built by FCC and OHL, the head of the Catholic Church and Vatican City addressed the millions of young people who were present as well numerous people who watched the ceremony on television.