The imposing KoepelKathedraal (DomeCathedral) was designed by architect Joseph Cuypers (son of the famous Dutch architect Pierre Cuypers) and built between 1895 and 1930. The church - also called the Notre-Dame of the Netherlands - is one of the five most important churches of its time: Sagrada Familia in Barcelona, the Sacré-Coeur in Paris, the Westminster Cathedral in London and the Basilica of Koekelberg in Brussels. The church is the second largest Roman Catholic church in the Netherlands.

The cathedral has no less than 12 large and small towers and a dome 65 meters high; on the inside almost as high as St Peter's in Rome. The cathedral was built in three periods. This is reflected in the various architectural styles, such as neo-Gothic, neo-Romanesque, Jugendstil and style elements of the Amsterdam School. Moorish influences can also be seen in the exterior and interior. The cathedral houses many art treasures. Over the past 100 years, more than 50 artists have worked on the cathedral.

The church is the cathedral of the Roman-Catholic diocese of Haarlem-Amsterdam and is dedicated to St Bavo, the patron saint of the city of Haarlem. In 1948, the KoepelKathedraal - then called Sint Bavokerk - was elevated to a basilica by Pope Pius XII. In 2019, the name of the church was renamed KoepelKathedraal, to avoid confusion with the Grote of St.-Bavokerk in the centre of Haarlem as much as possible

The church also houses a small museum, exhibiting historical artifacts from Haarlem’s Catholic past.