Ergo Arena (Hala Gdańsk-Sopot) is a multi-purpose indoor arena, that was opened in 2010. The boundary between two cities – Sopot and Gdańsk – runs through the very middle of the hall. The arena has a capacity of 11,409 people, for sports events and up to 15,000, with standing places, for concerts.On November 26, Lady Gaga performed during The Monster Ball Tour, with Semi Precious Weapons as her opening act, to more than 12,000 people. It was the first big event to take place in the hall.