The dining-entertainment venue, based on the Greek taverna featured in the Abba-themed film Mamma Mia!, is the idea of Abba star Bjorn Ulvaeus.

He was joined for the opening night by Benny Andersson, Anni-Frid Lyngstad, and Agnetha Faltskog.

They were last seen in public together in 2008, news website thelocal.se said.

Fans and guests paid 1,340 kronor (£110; $157) for a ticket to the opening night of Mamma Mia! The Party at the Tyrol restaurant in Grona Lund, Stockholm, on Wednesday, it added.

(BBC News)