Location:
Urcos Lake is situated at the northern limit of the small town of Urcos, about 40 kilometers southeast of the former Inca capital, Cusco, in the southern Andes of Peru at 13°41' southern latitude and 70°38' western longitude at an altitude of 3,180 meters.

Lake Huacarpay is situated at around 26 kilometers, southwest of Cusco at 13°37' southern latitude and 71° 44' western longitude at an altitude of 3,170 meters. Huacarpay is actually formed by three lakes separated from each other by a swampy reed grass area .

Year of expedition: 2002

Participants:
Johann Reinhardt, National Geographic Associated Arqueologist
Stefan Austermühle
Jean Paul Perret
Jose Galván

Goal:

The purpose of the expedition was to make a detailed survey of underwater archeological remains within Lake Urcos and Huacarpay, using a sediment sonar technology and verifying the information collected by scuba diving.

Short historical summary:

Lake Urcos is known as the lake where the Incas were hiding a "golden chain". The stories written down by Spanish chronics say that Huascar emptied the lake by constructing a tunnel, constructed a building on the lake's seabed, where he stored large quantities of gold and flooded the lake again in order to hide away the gold from his brother, with whom he was at war. The Spaniards gave that much credibility to the story that they attempted themselves to dig a tunnel and empty the lake, which was frustrated when they hit hard rock that did not permit further digging.

Huacarpay is the birthplace of the Inca Huascar. The ruins of his palace are situated on the south western edge of the biggest of the three lakes forming Huacarpay. According to the archeological surveys existent in the area, it was estimated by Johan Reinhard and the local INC representatives that most probably archeological remains within the lagoon should be situated in the southern half of the biggest lake of Huacarpay, right in front of Huascars birthplace. There were no specific legends indicating archeological remains in this lake.

Results:
Lake Urcos
Lake Urcos has been screened in a very detailed manner with 143 recorded profiles taken in 6 days. Wall like structures of several meters of extension and heights at different locations in the lake's sediment could be positively identified by scuba diving as fragments of natural platforms formed by the roots of reed grass, being ripped off by mudslides or being separated by aging and growth processes from the reed grass belt along the shoreline and having sunk to the lakes bottom, "sticking" vertically in the lakes sediment. The profile of the lake is extremely even. There is a steep fall on all sides of the lake to a depth of 14 meters. The rest of the lake's bed is formed by a flat plane with an average depth of approximately 15 meters. The lake has a maximum depth of 15.4 meters. No archeological remains like walls, man-made structures or other large remains within the lake's sediment up to a depth of two meters could be identified.

Graphic 7: Three dimensional map of seafloor of lake Urcos, Each color represents a depth
Maximun depth 15.4 mt. @ Stefan Austermuhle

Lake Huacarpay

Lake Huacarpay is much bigger than Lake Urcos and the time available was shorter. A total of 89 profiles were recorded within 5 days of survey. The dense screening concentrated on the southern part of the lake, while the northern half was less densely surveyed. While Lake Hacarpay, with a maximum depth of 8.6 meters is much shallower than Lake Urcos, it's profile is much more complicated with different areas of the lake having different depths and being separated by "ridges". Comparing with the results from Lake Urcos, the survey comes to the conclusion that several small wall-like structures (maximum altitude 1 meter) are similar reed grass root conglomerates than in Lake Urcos. No larger archeological remains or man-made structures within the first two meters of sediment depth in that lake could be identified.

Graphic 47: three dimensional map of Lake Huacarpay. Colors are indicating depth
Maximun depth 8.6 mt. - @ Stefan Austermuhle / Mundo Azul