In constructing the large church, advantage was taken of a beautifully laid wall of close-fitting ashlars.  Incahuasi was well named; there had been at one time an Inca house here, possibly a temple—­lakes were once objects of worship—­or rest-house, constructed in order to enable the chiefs and tax-gatherers to travel comfortably over the vast domains of the Incas.  We found the slopes of the hills of the Parinacochas Basin to be well covered with remains of ancient terraces.  Probably potatoes and other root crops were once raised here in fairly large quantities.  Perhaps deforestation and subsequent increased aridity might account for the desertion of these once-cultivated lands.  The hills west of the lake are intersected by a few dry gulches in which are caves that have been used as burial places.  The caves had at one time been walled in with rocks laid in adobe, but these walls had been partly broken down so as to permit the sepulchers to be rifled of whatever objects of value they might have contained.  We found nine or ten skulls lying loose in the rubble of the caves.  One of the skulls seemed to have been trepanned.

On top of the ridge are the remains of an ancient road, fifty feet wide, a broad grassy way through fields of loose stones.  No effort had been made at grading or paving this road, and there was no evidence of its having been used in recent times.  It runs from the lake across the ridge in a westerly direction toward a broad valley, where there are many terraces and cultivated fields; it is not far from Nasca.  Probably the stones were picked up and piled on each side to save time in driving caravans of llamas across the stony ridges.  The llama dislikes to step over any obstacle, even a very low wall.  The grassy roadway would certainly encourage the supercilious beasts to proceed in the desired direction.

In many places on the hills were to be seen outlines of large and small rock circles and shelters erected by herdsmen for temporary protection against the sudden storms of snow and hail which come up with unexpected fierceness at this elevation (12,000 feet).  The shelters were in a very ruinous state.  They were made of rough, scoriaceous lava rocks.  The circular enclosures varied from 8 to 25 feet in diameter.  Most of them showed no evidences whatever of recent occupation.  The smaller walls may have been the foundation of small circular huts.  The larger walls were probably intended as corrals, to keep alpacas and llamas from straying at night and to guard against wolves or coyotes.  I confess to being quite mystified as to the age of these remains.  It is possible that they represent a settlement of shepherds within historic times, although, from the shape and size of the walls, I am inclined to doubt this.  The shelters may have been built by the herdsmen of the Incas.  Anyhow, those on the hills west of Parinacochas had not been used for a long time.  Nasca, which is not very far away to the northwest, was the center of one of the most artistic pre-Inca cultures in Peru.  It is famous for its very delicate pottery.