thumb|upright|Westwork of [[Corvey Abbey]]
A westwork (), forepart, avant-corps or avancorpo is the monumental, west-facing entrance section ("west front") of a Carolingian, Ottonian, or Romanesque church. The exterior consists of multiple stories between two towers. The interior includes an entrance vestibule, a chapel, and a series of galleries overlooking the nave. A westwork is usually broader than the width of the nave and aisles. It is sometimes used synonymously with narthex. The structural purpose of the massive westwork is to resolve the horizontal thrust of the east-to-west arcades of the nave. Church towers as a part of a church began with the construction of the first westworks.
Charlemagne dreamt of reviving the Roman Empire in the West. His dream along with his artistic skillset allowed him to implement artwork into buildings with westwork during this time period The frescos (originally of the 9th century) inside the westwork show scenes from the Odyssey. The King, later the Emperor, and his entourage lodged in the westwork when visiting the abbey during their travels around the country. This is known as the Kaiserloge on the upper, or second story. The centered room located on the main floor surrounded on all three sides by galleries as well as an arch found in the entrance hall of the Corvey Abbey shows an example of ancient styles used during this time.