Helsinki Cathedral is an Evangelical Lutheran cathedral of the Diocese of Helsinki, located in the centre of Helsinki, Finland. The church was originally built as a tribute to the Grand Duke, Nicholas I, the Tsar of Russia and until the independence of Finland in 1917, it was called St. Nicholas' Church.
A distinctive landmark in the Helsinki cityscape, with its tall, green dome surrounded by four smaller domes, the building is in the neoclassical style. It was designed by Carl Ludvig Engel as the climax of his Senate Square layout: it is surrounded by other, smaller buildings designed by him.
Today, the cathedral is one of Helsinki's most popular tourist attractions. More than 350,000 people visit the church each year, some to attend religious events, but mostly as tourists. The church is in regular use for services of worship and special events such as weddings.