On our second day we hiked the Inca trail up to the Sun Gate. During the December Solstice (southern hemisphere's summer solstice), the sun rises through the Sun Gate and illuminates the altar in the Temple of the Sun in the city below.
A close-up view of the top of Huayna Picchu (the trail we decided not to take.)
A wider view of the trail to the Inca Bridge. A gate prevents anyone from going to the bridge and beyond -- the trail is perilous.