IT is the city that helped define their lives and careers.
And the Lisbon Lions say their return to Portugal will help them re-live their achievements when Celtic scooped the European Cup after defeating Inter Milan 2-1 in 1967.
Earlier this year the club invited the winning team to Lisbon for this Saturday's UEFA Champions League Final between Spanish giants and local rivals Real and Atletico Madrid.
During their visit the team will attend the game as well as visit the Estadio Nacional, the scene of their greatest victory.
Members of the squad gathered in Celtic Park yesterday ahead of the trip.
Lisbon Lions captain and Celtic Ambassador Billy McNeill said: "This is a magnificent gesture by the club and one which is greatly appreciated by all the boys and the families of everyone connected to the team.
"It will be fantastic for us all to re-live what we achieved on that great day in Lisbon in 1967.
"As Club Ambassador I am privileged to travel throughout Europe proudly representing Celtic. This time, however, I will be travelling with my team-mates as part of the Lisbon Lions.
"It is always an emotional occasion when we meet up but this time it will be more so as it will be in the city where we made history all those years ago."