On April 9, 1965, the fifty members who attended the Extraordinary Assembly called by the president, Jacinto Saldise, were going to make a decision that would mark the future of Club Atlético Osasuna: the sale of the San Juan field and the construction of a new stadium. The revaluation of the land due to the urban development of the Tercer Ensanche and the economic debt that the club was carrying, which forced the sale of valued players such as Ignacio Zoco, Félix Ruiz and Pedro Mari Zabalza, were important factors for the field that had seen Osasuna grow as an entity and as a team for a little over forty years, to say goodbye soon.

The curtain came down on May 7, 1967, with a 2-0 victory in a cup match against Elche; Fanjul and Beci were the last scorers, before the bulldozers brought the stands and bleachers to the ground.

Location; Soto del Sadar

Once the decision was made to leave San Juan, it was essential to locate land large enough to house the new stadium and its annexed sports facilities. The board Board of Directors studied various sites: land near the Civil Hospital, in Mendillorri, in Mutilva and in the Soto de
One of the great novelties was the artificial lighting, with four towers with 36 floodlights.
Lezkairu. Finally, the site chosen was the Soto del Sadar, in a large area of the Southern Plan that had been classified as a sports area.

A new page in the history of Osasuna would begin to be written in this location, well statement although far from the urban center as San Juan was in its day.

The project: the plans of Tomás Arrarás
board The project of the new stadium was entrusted to the Pamplona architect Tomás Arrarás Larrea, the same architect who in 1956 had designed the plans for the last renovation of the San Juan stadium, which had provided it with a capacity for 20,000 spectators.
A great Osasuna fan, Arrarás proposed an enclosure that would fit as much as possible to the Philosophy of a team and a fan base like those of Osasuna. That is why he conceived a stadium that maintained the spirit of San Juan, with a very similar capacity and dimensions of the pitch, and stands close to the pitch so that the fans' encouragement could be felt as strongly as possible. In addition, achieving maximum visibility and comfort were the two guiding principles of project.

The architect signed the final plans between August and October 1966. The total capacity reached 23,283 spectators, of which 7,334 were seated and the remaining 15,949 standing. With a reinforced concrete structure for the entire field, the stands were characterized by their homogeneity as a whole, and were protected by a metal roof that was raised on iron posts, an element that Arrarás considered indispensable for a rainy climate like that of Pamplona.

The exterior enclosure of the stadium was sober and functional, forming a portico, with brick walls and lattices and metal access doors. There was only a small concession to ornamentation on the facade of the Grada Lateral, where the club's coat of arms was installed along with the name and year of inauguration of the stadium. The flagpoles of the teams' flags were also placed here, the order of which reflected the order of the standings.

Construction: with four light towers

After overcoming several bureaucratic formalities, the works began in October 1966 at position of the business construction company Erroz, SA, which in less than a year carried out the construction works. A total of 14,000 cubic meters of concrete were used, including 500,000 kg of iron, and another 350,000 kg for the roof structure.
One of the great novelties was the artificial lighting, which was installed by signature Ignacio Soria, SA. Four 38-meter-high towers were erected in the corners of the stadium, each with 36 light projectors, plus another 38 floodlights on the sidelines. Finally, Osasuna could finally play matches at night, something that was impossible in San Juan due to the lack of artificial light.

Contributing to the magnificent image of the new stadium was its manicured turf, unique in Spain for its composition of four different grasses.

Inauguration: triangular tournament

At the end of the works, and as a preamble to the start of the 1967-68 season, the inaugural ceremony of the stadium took place, for which the red and white club organized a triangular tournament with the participation of Real Zaragoza and Vitoria de Setúbal, champions of the Portuguese Cup; the latter replaced Español, who could not attend the tournament as planned due to a last minute change of dates. Thus came Saturday, September 2, 1967, a day core topic in the history of Osasuna. At seven o'clock in the evening, in the presence of the National Delegate of Education Physical and Sports, Juan Antonio Samaranch, and the president of the Spanish Football Federation, José Luis Costa, the parish priest of San Fermín, Mr. Tomás Esarte, blessed the stadium, in a protocol act that counted with the presence of the group dance group of the City Council and the Pamplonesa music band. The kick of honor was given by the Osasunista president Jacinto Saldise. Afterwards, the inaugural match pitted Zaragoza against Vitoria de Setúbal, who drew to a one-goal draw. The Portuguese Pedras was the first to put the ball in the net, and Marcelino equalized after heading in a cross from Canario.
Osasuna played their first match at the Sadar the following day, defeating Vitoria de Setúbal 3-1, with goals from Fernando Osaba twice and Jordana. In the end, the trophy went to Zaragoza, who beat Los Rojillos in the final match by 0-3.

The changes: the enclosure, promotions and demotions

Since then and up to the present day, the stadium has undergone successive renovations: installation of protective fences (1977-78 season), construction of the new High Preference Stand (1989-90 season), adaptation to rules and regulations UEFA in subject for safety and modernization of the stadium (a process that culminated in 2003) and even the change of name of the stadium, from El Sadar to Reyno de Navarra, in December 2005.

And, as it could not be otherwise, it has witnessed disparate situations: from the wandering in the Third Division, to the unforgettable promotions and the salvations in the last workshop, celebrated as much or more than if it were a promotion. Without forgetting the participations in the UEFA Cup, which Osasuna disputed for the first time in the 1985-86 season managing to overcome the first elimination round against Glasgow Rangers. Or the preliminary round of the Champions League, with the painful elimination at the hands of Hamburg, which however marked the beginning of an exciting trajectory in the 2006-07 UEFA, beating teams like Girondins Bordeaux, Glasgow Rangers and Bayer Leverkusen, until being eliminated in the semifinals by Sevilla.

Having reached a thousand official matches, El Sadar continues to be the hallmark of a club, a team and a fan base that, both in good times and bad, remains loyal to the Osasuna team. This is undoubtedly a reason to celebrate, and to continue trusting in the strength that the stadium transmits in each match to the red and white players to bring them closer to victory.