I want to know the answer to the following question:
When was the biggest cathedral in Switzerland built?
All the background I'm provided with is that "Some of the most notable in the Old Town include the Cathedral which was started in 1421 and is the tallest cathedral in Switzerland, the Zytglogge and Käfigturm towers, which mark two successive expansions of the Old Town, and the Holy Ghost Church, which is one of the largest Swiss Reformed churches in Switzerland.". Is that enough to answer the question?