The Church of St. Johannes in the Kirdorf district is often referred to as the Taunus Cathedral. Built between 1858 and 1862, it is considered one of the last large sacred buildings in the late classicist round arch style in Germany, before this was finally replaced by the neo-Romanesque and neo-Gothic styles. The building can be viewed as an independent creative achievement of the 19th century, in which the architect, the Mainz cathedral builder Ignaz Opfermann (1799-1866), succeeded in modifying the Byzantine style. Characteristic of the classicist tradition of the round arch style is the striving for symmetry, the almost completely identical design of the building parts on both sides of the longitudinal axis, the lack of formal variation in the details and the position and arrangement of the towers. The building is located in the middle of the town on a hillside. The three-aisled complex with a two-tower facade with a vestibule and anteroom has a wide central nave and two side aisles half as wide, which end at the rear with two side chapels. Four slender pillars support the vaults, which are formed as a flat dome. The vaults are supported by four octagonal pillars on high bases with profiled ends. The pillars have lavishly decorated capitals, the decoration of which consists of tongue leaf and palmette ornaments, angel heads and palmette friezes.