Long before the Incas existed, there was a culture that flourished in La Libertad called the Mochicas.  They were very good in art and made wonderful pots that can still be seen in museums.  Even though there is a lot of impressive things in this culture, the Huaca del Sol is for many people the most impressive of them all. 
The Huaca del Sol was built on the edges of the Moche River Valley in the department of la Libertad.  The ruinswere found and explored by  archaeologist Max Uhle during the years 1898 and 1899.  The Huaca del Sol was a very large adobe structure that measured about 345 meters by 160 meters but was destroyed by the rains that occurred after they were built.  About 140 million adobe bricks were put together to make up the pyramid named after the Moche’s god, the Sun.
         Inside the pyramid, archaeologists found many tombs stacked neatly on top of one another.  Archaeologists came to the conclusion that the Huaca del Sol had been a cementery for many cultures because the art on the tombs belonged to different cultures including Incas, Chimu and Moche.  The Chimu’s were the Moche’s successors.  For that reason, it is believed that the Moches were the ones that created such a wonderful adobe structure. 

Bibliography:

"The Ancient Moche Culture." Company Not Available.March 18, 2002.<http://multimedia.esuhsd.org/2000/ed_project/135_web/studentprojects/moche/>

" Trujillo, Peru." Andex Tours.March 18, 2002.<http://www.andextours.com/trujillo.htm>

"La Huaca del Sol y de la Luna." Jay A. Fogel Copyrighted. March 25, 2002. <http://www-astronomy.mps.ohio-state.edu/~frogel/Peru98/Peru98_Huaca_del_Sol/0Peru98_Huaca_del_Sol_home.html>

"Las Huacas del Sol y de La Luna." Personal Page. March 25, 2002. <http://www.ideasmultiples.com/huacas/>