Cayambes’ were not cowed but gave a brave fight which eventually forced the Incas to lift the siege as they had lost many men in the fight. However, the Incas finally defeated the Cayambes and forced them to retreat to the shores of the lake Yawarkucha. It is also said that the Incas cut the throats of their enemies and threw them into the lake, which turned red with blood, and thus the lake got the epithet "Yawarkucha" meaning "blood lake". This aspect of the legend is to be confirmed by further explorations by archeologists examining the areas. Geography Jorge Juan y Santacilia and Louis Godin, on their voyage through South America to fix signals for surveys, arrived at the "desert of Pambamarca" in early September 1737. A mountain of medium height in this desert is also named Pambarmarca. One of the largest group of fortresses (on the hill which is called locally as pukaras) seen in Ecuador was the Pambamarca Group located along a ridge running in a north–south direction. These military structures provided security to Quito fortress and other forts such as Jambimachi, Pambamarca, Pachha, Campana, Olachan Tablarumi, Achupallas, Guachala and Bravo. Cloudbow From the top of the Pambarmarca mountain, a strange weather phenomenon was noticed by Don Jorge Juan and Antonio de Ulloa and several other climbers who had gone there to establish signal posts for surveys. As the cloud covered hills became clear of the clouds and frost with the Sun rising, each person on the hill top started noticing his own image at distance of about 10 miles opposite to the Sun. In this image, the head of each one of them appeared (individually) within the centre of three concentric irises (with colours coalescing with each other) as if each one, individually, was seeing his mirror image; these were perpendicular to the horizon. An arch in white colour was seen at a distance from the three irises, circumscribing them. The diameter of the central iris was initially measured as 5.5 degrees while the arch around the circles was 57 degrees in size. Initially, the arches were seen in oval shape and as the Sun rose above the horizon it changed to a perfect circular shape, like the disc of the Sun. The arches displayed red colour bordered by orange colour, followed by bright yellow becoming straw colour and finally into green. However, the outer arch