The old San Mamés, also known as La Catedral, was opened on 21 August, 1913 and become one of the most historic and special stadiums in all of football. The first match played at the stadium was a friendly against Real Unión in what was a rematch of the 1913 Copa del Rey final, and the first goal at the San Mamés was scored by legendary striker Rafael Moreno Aranzadi, also known as Pichichi.
With a capacity of over 40,000 the San Mamés was one of the premier stadiums in all of Spain and an extremely difficult place to play for visitors. Fans always said that there was something mystical and magical about the grounds which added to the legacy. The stadium received a renovation in 1952 and was almost completely rebuilt in 1982 in order to host matches for the World Cup.
In March of 2006 a project was approved to begin building a new and modern stadium and the club began construction in April of 2010. The final official game was played on 26 May, 2013 in a 1-0 loss to Levante. There was also a time of celebration with players and fans alike shedding tears for the nearly century old stadium. Fernando Llorente was the last Athletic player to score an official goal at the San Mamés which took place in the previous match. Before demolition, Athletic played a farewell friendly game on 5 June, 2013 against a Bizkaian XI (comprised of players from Bizkaia but from other clubs). Former legends such as Julen Guerrero and José Ángel Iribar were there to walk on the pitch one last time while others such as Rafael Iriondo were in attendance to say goodbye. After the friendly demolition began but the iconic Arch was salvaged and placed at the Lezama training facilities. Also during demolition, a piece of turf and a brick from the foundation were taken and passed by a human chain of legendary players, current players, academy members, and supporters to the site where the new stadium was already under construction. At the time of demolition the San Mamés was the older stadium stadium in Spain.
The new San Mamés was constructed next to where the original stadium stood and was inaugurated and opened on 16 September, 2013 although it was only 75% finished at the time. The first game took place 102 days after the final match at the old stadium and Athletic defeated Celta Vigo 3-2 to claim their first victory. Mikel San José had the honor of being the first Athletic player to score at the new grounds while the deciding goal coming from Beñat, both formerly trained at Lezama. Keeping with tradition, clubs coming to play at the San Mamés for the first time still have their captain lay a bouquet at the statue of Pichichi which stands near the player’s tunnel.
After one year the rest of construction was completed and Athletic played their first match in the full stadium on 27 August, 2014 in a 3-1 win over Napoli to advance to the next stage of the Champions League. With a capacity of over 53,000 the new San Mamés has become one of the premier stadiums in all of Europe. The exterior contains a world-class lighting system capable of illuminating in any color and showing graphics, as well as a large screen and a giant crest that overlooks where the original stadium stood. The club museum was also opened in August of 2017. Since opening, the new San Mamés has been recognized for its grandeur by being selected to host prestigious events such as the 2018 European Rugby Challenge Cup and Champions Cup, while also being named as one of the 13 venues that will host matches in EURO 2020.