The main church of Kotka is an Evangelical Lutheran cathedral, built in 1898 of red brick in neo-Gothic style to the design of Josef Stenbeck. Inside there are 1,560 seats. The spacious building is 54 metres high, with magnificent stained glass windows, beautiful ornamentation on the columns and marvellous carved wooden interior serves as a concert hall for organ music.
The church organ, which has 44 registers, was made by Marty Portanen in the Baroque style, modelled on the organ of Freiberg Cathedral in Germany, was installed in 1998 to mark the centenary of the church's centenary. The altar icon "Adoration Adoration of the Magi", painted by Pekka Halonen, depicts the infant Jesus.
The main church of Kotka belongs to the Diocese of Mikkeli. Visitors are offered guided tours.
