It has been the capital of the half-canton of Appenzell Ausserrhoden since the division of the national territory in 1597. The centre is formed by the main square, where conspicuous stone buildings are interspersed with individual wooden houses.

Trogen is a village that has seen strong commercial and building development over the centuries, largely due to the influence of the Zellweger family. The municipal area stretches from Eugst, an area that was once ecclesiastically dependent on Altstätten, to St. Gallen. The area of Eugst was mainly settled from the Rhine Valley, while the remaining part of the municipality came from migrants from St. Gallen. The village evolved over time, becoming an important political and cultural centre, especially after Trogen became the capital of Appenzell Ausserrhoden in 1597, the seat of institutions such as the Landsgemeinde and the court. The heart of the village is dominated by the Evangelical church, located at the north-eastern end of the main square. The church, built between 1779 and 1782, is characterised by its elongated rectangular floor plan and a polygonal choir. The bell tower, located on the left side of the choir, gives the building a harmonious appearance. The façade, characterised by columns and an elegant arched gable, reflects the transition from the Baroque to the Neo-Classical style, with timeless simplicity and beauty. Also on the same square are the parish house and the town hall, which, with its neo-classical cubic form and the frescoes in the ballroom, enriches the architecture of the village. Next to the church, the old Zellweger Palace bears witness to the historical importance of the family that contributed to the progress of the town. The town hall, built at the beginning of the 19th century, is one of Trogen’s most emblematic buildings, with its ballroom adorned with portraits of important local personalities. Another point of interest is the Arsenal, built in 1824 on the old main road, which adds a touch of historical charm to the village landscape. Trogen is a place that, despite its calmness, tells stories of change and growth through its architecture and monuments.