Continuing from the Caretaker’s Hut [1], follow the Inca Trail [2] downhill to the Main Gate to Machu Picchu. A gigantic entrance door with locks on the inner part of the door was used to close Machu Picchu [3].
Passing the Main Gate, continue on for about 40 meters, where, to your right, you will find a building with many doors on the first floor. The ground floor of this building was probably used as a meeting area, while the second floor was a storage room where produce was dried by ventilation. Below these storehouses, there are more than 15 constructions on different levels that were used as housing.
Going back up to the main trail, continue three minutes until you arrive at an open area with numerous rocks. This area is the quarry [4] of Machu Picchu.
Links:
[1] http://www.moon.com/destinations/peru/machu-picchu/ruins-tour/caretaker-s-hut
[2] http://www.moon.com/destinations/peru/machu-picchu/machu-picchu-hikes-and-treks/inca-trail
[3] http://www.moon.com/destinations/peru/machu-picchu
[4] http://www.moon.com/destinations/peru/machu-picchu/ruins-tour/quarries