With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Machu Picchu is a 13th-century Inca citadel.
text_B: Machu Picchu -LRB- -LSB- ˈmatʃu ˈpitʃu -RSB- -RRB- -LRB- Machu Pikchu -LSB- ˈmɑtʃu ˈpixtʃu -RSB- -RRB- is a 15th-century Inca citadel situated on a mountain ridge 2430 m above sea level .. Inca. Inca Empire. above sea level. Above mean sea level. It is located in the Cusco Region , Urubamba Province , Machupicchu District in Peru , above the Sacred Valley , which is 80 km northwest of Cuzco and through which the Urubamba River flows .. Peru. Peru. Cusco Region. Cusco Region. Urubamba Province. Urubamba Province. Machupicchu District. Machupicchu District. Sacred Valley. Sacred Valley. Cuzco. Cuzco. Urubamba River. Urubamba River. Most archaeologists believe that Machu Picchu was built as an estate for the Inca emperor Pachacuti -LRB- 1438 -- 1472 -RRB- .. Inca. Inca Empire. archaeologists. archaeologists. Pachacuti. Pachacuti. Often mistakenly referred to as the `` Lost City of the Incas '' -LRB- a title more accurately applied to Vilcabamba -RRB- , it is the most familiar icon of Inca civilization .. Inca civilization. Inca Empire. Inca. Inca Empire. Vilcabamba. Vilcabamba, Peru. The Incas built the estate around 1450 but abandoned it a century later at the time of the Spanish Conquest .. Spanish Conquest. Spanish conquest of the Inca Empire. Although known locally , it was not known to the Spanish during the colonial period and remained unknown to the outside world until American historian Hiram Bingham brought it to international attention in 1911 .. Hiram Bingham. Hiram Bingham III. Machu Picchu was built in the classical Inca style , with polished dry-stone walls .. Inca. Inca Empire. Its three primary structures are the Inti Watana , the Temple of the Sun , and the Room of the Three Windows .. Inti Watana. Inti Watana, Urubamba. Most of the outlying buildings have been reconstructed in order to give tourists a better idea of how they originally appeared .. By 1976 , thirty percent of Machu Picchu had been restored and restoration continues .. Machu Picchu was declared a Peruvian Historic Sanctuary in 1981 and a UNESCO World Heritage Site in 1983 .. UNESCO. UNESCO. World Heritage Site. World Heritage Site. In 2007 , Machu Picchu was voted one of the New Seven Wonders of the World in a worldwide Internet poll .. New Seven Wonders of the World. New Seven Wonders of the World#Winners
related.