Borussia Dortmund's "Yellow Wall" -- the South Stand at Signal Iduna Park -- has been described as a 'gigantic monster' ready to intimidate opposing teams.
Packed with passionate home fans, Borussia Dortmund's imposing south stand - dubbed 'The Yellow Wall' - is the 'gigantic monster' lurking to test Paris Saint-Germain stars like Neymar and Kylian Mbappe in the Champions League on Tuesday.
"It's just a fantastic feeling that I haven't had before," is how Dortmund's star striker Erling Braut Haaland described scoring in front of 'Die Gelbe Wand' (The Yellow Wall) at Signal Iduna Park.
The 19-year-old has bagged nine goals in six games since Dortmund snapped him up for 20 million euros ($22 million) from Salzburg.
Five of them have come in his three home appearances games, including one in the 4-0 thrashing of Frankfurt on Friday.
"If you are the opposition, it crushes you -- but if you have her at your back as a goalkeeper, it's a fantastic feeling," is how ex-Dortmund shot-stopper Roman Weidenfeller describes the experience of the imposing terrace.
For Bundesliga games, the south stand, which is 100 metres (328 feet) wide and 40 metres high, is packed with 25,000 fans, but capacity is reduced to 16,000 to meet UEFA regulations for Champions League games.
- 'Huge, roaring monster' -
Nevertheless, the noise will be deafening when the Dortmund team walk out for Tuesday's last 16, first leg tie.
PSG boss Thomas Tuchel, who coached Dortmund for two seasons until 2017, knows what to expect.
"We have a few boys used to the stadiums of this world and whom I trust to play their best, on this stage as well," the 46-year-old told German daily Welt on Sunday.
"I know very well what energy is waiting for us there."
'The Yellow Wall' already has an international reputation.
"Just look at the south stand in Dortmund," Johnny Rotten, lead singer of British punk band The Sex Pistols has said on the matter.
"They all stand, chant and make such a noise that the stand seems like the pharynx of some huge, roaring monster. It's fantastic."
Dortmund fan Max Kiwit, 27, told AFP why he is a regular on 'The Yellow Wall'.
"Because here, everyone can let go of their emotions. No one will complain if they get elbowed in the head" or if they get showered by beer when Dortmund score to send thousands of plastic cups flying, he said with a smile.
Season tickets for the south stand start at 219 euros ($237), but are often passed down from generation to generation.
The waiting list is often counted in years, as Max's girlfriend Sabrina Rupp discovered to her cost.
"Until I was 13, I had a season ticket," she admits regretfully.
"I gave it back, and that's the worst mistake you can make, because after that it's almost impossible to get it back."
'The Yellow Wall' is often described as the beating heart of Signal Iduna Park.
It's from there that designated fans lead the chants, yelling into megaphones while drummers beat out the rhythm.
The fans in the south stand sees themselves as the 12th man of the Dortmund team.
- Malaga mayhem -
On the run to the 2013 Champions League final, where Dortmund lost 2-1 to Bayern Munich at Wembley, the wall played a key role in the quarter-final at home to Malaga, when the hosts found themselves 2-1 down with 90 minutes on the clock.
With Dortmund seconds from elimination, the fans erupted, inspiring tired legs to one last push.
Pandemonium broke out when forward Marco Reus, then defender Felipe Santana grabbed goals in added time to seal a fairytale 3-2 win after a goalless first leg in Spain.
The delirious scenes at the final whistle are part of club folklore.
Former Dortmund coach Jurgen Klopp explained what the PSG team can expect on Tuesday.
"You come out and the stadium explodes... you look to your left and it looks like 150,000 people are standing there going crazy," said Klopp, who led Dortmund to back-to-back Bundesliga titles in 2011 and 2012.
As the Malaga game demonstrated, PSG need to play until the final whistle as Dortmund can never be written off with their backs to 'The Yellow Wall'.