“Fans are close to the pitch and really in sync with the players,” explains Gaizka Atxa, founder of a supporters’ group named after Fred Pentland, a legendary former English coach of the club.

“The environment is usually overwhelming for rivals that come to San Mames. It’s intimidating, especially in La Liga. In Spain, I don’t think there’s a similar type of environment.”

The San Mames experience, though, begins long before kick-off. On the bar-lined ‘Poza’, supporters dripping in red and white go through their pre-match routines, meeting for drinks and pintxos, buying their sandwiches for half-time, something of an Athletic tradition.

“When Athletic is performing really well, the pre-match atmosphere is second to none,” says Atxa. “People are always socialising, friends getting together and trying to have a good time and enjoy themselves, that experience of hanging out before the match, that’s really what a lot of fans really like.

“Once you get into the Athletic culture, people really enjoy the socialising before the match and that really gets you into a good spirit.”

Built on the site of the old stadium, the new San Mames, opened in 2013, is both ideally located within walking distance of the city and a stone’s throw from the River Nervion.

It’s a site packed with history and one where legends are celebrated.

A statue of former goalkeeper and captain Jose Angel Iribar stands in front of the ground – it was Iribar and Real Sociedad captain Inaxio Kortabarria who carried a banned Basque flag on to the pitch before a derby in December 1976, following the death of Spanish general Francisco Franco.

Meanwhile, the bust of Rafael Moreno Aranzadi, better known as Pichichi, Athletic’s prolific forward in the early 20th century who La Liga’s top goalscorer award is named after, sits at the entrance of the players’ tunnel.

“With Pichichi, we are talking about a legend, one of the most iconic players for Athletic and someone who transcends Athletic to be an important piece of Spanish football culture,” says Gutierrez.

“Iribar goes even beyond that. He is a legend, but he is currently the embodiment of the values of Athletic. He is the most important representative of the club.

“He is the person any fan is so happy to see around. He is always there to show Athletic is with the people, he is someone like no other in Athletic’s history.”