Petriplatz is located between Breite Straße and Gertraudenstraße and was once the historical centre of Cölln, medieval Berlin's sister city. The square is named after St Peter, the patron saint of the fishing folk who lived on nearby Fischerinsel. Today, there's almost nothing left of the once-thriving business and residential centre. But excavations started in 2007 have begun to unearth the foundations of the old St Peter's church, the Latin school, the remains of Cölln's town hall, medieval town houses and tombs. There are numerous construction projects under way to revive Petriplatz. The large streets that cut through Petriplatz will be partially scaled back and new buildings erected on the historic site surrounding a restored Petriplatz and parks. At the same time, an archaeological centre and a house of prayer and teaching House of One will be built on Petriplatz. This project will combine prayer rooms for Christians, Jews and Muslims and promote dialogue between the religions.