History
Tiefencastel is first mentioned in 831 as in Castello Impitinis. Starting around in the 14th century it was known as Tüffenkasten.
Geography
Before the merger, Tiefencastel had a total area of 14.9 km2 (5.8 sq mi). Of this area, 20.3% is used for agricultural purposes, while 49.6% is forested.