Where they were found
Inca mummies consist of at least three main types:
(1) the mummies of the rulers. Most were kept in Cusco, though at least the mummies of three kings were sent to Lima. None have ever been found, because they were destroyed during the Spanish conquest of Peru.
(2) the mummies of sacrificed children, which have been found on mountain tops in Peru, Chile, and Argentina. One was named Juanita, the Ice Maiden.
(3) A related group of Inca mummies are the Chachapoya, known sometimes as the mummies of "the Cloud People." These come from northern Peru.
When they were made
The mummies of the rulers and mountain top sacrifices were made from 1438 to 1532, during the reign of the Inca empire.
How they were made
(1) The mummified rulers were most likely artificial mummies, although the methods the Inca are unclear. The dead king would have been seated on a special throne, arms across his chest, knees brought up to the chest. Pieces of silver and gold would have been placed on his chest and in his hands and mouth. He would have been dressed in fancy cloth. But no record of the actual mummification process (was the body dried? was it treated in any way? were internal organs removed?) was recorded.
(2) Children who were sacrificed on the mountain tops became natural mummies, because of the freezing temperatures and the dry, windy mountain air.
How many were made
There are no estimates of how many Inca mummies were made.
What's special about them
1. The artificial mummies of the Inca rulers are special because they no longer exist. When the Inca were conquered by Pizarro, he ordered his soldiers to burn the mummies. Devout Catholics, he was disturbed by the Inca worship of their dead ancestors. With their destruction went valuable information not only about the mummification process but the lifestyle and civilization of the Inca rulers.
2. The natural mummies of the mountain top sacrifices are special because (1) so many have been found in recent years and (2) some of the mummies are in excellent condition and (3) the burial items and even the platform itself can provide archaeologists and other researchers with important information about the Inca life and religious beliefs.
For example, three new Inca ice mummies were found in perfect shape in early spring 1999 during blizzard conditions atop Mount Llullaillaco, a 22,000-foot volcano in the Argentine Andes. The boy and two girls, between 8 and 15 years old, were discovered by archaeologist Johan Reinhard (and his National Geographic team), who also found Juanita in 1995. Dr. Reinhard has found 18 mountain top mummies in the Andes of Chile, Peru, and Argentina.
What's so exciting about these three mummies is that weather conditions caused them to be frozen rather than freeze-dried. This means that they are much better preserved--so well preserved that a CT-scan revealed that all of their internal organs are intact and in good shape, as if they had just died last week instead of approximately 500 years ago. In fact, the heart and lungs still contain blood. Reinhard said that the mummies "appear the best preserved of any mummy I've seen. The arms looked perfect, even down to the visible hairs." According to Reinhard, they are better preserved than Juanita. [NOTE: Freeze-dried mummies have no fluids left in their bodies for scientists to study.]
This perfect condition will allow researchers to study the mummies as thoroughly as possible (without harming them) and find out what they had eaten before death and even if they were genetically related. They do not even intend to unwrap the mummies completely.
Apparently the three were sacrificed by the Inca, though no cause of death has been determined yet. They may have even been buried alive--five feet below a burial platform. They were separated by stone walls, and the bodies were covered with rocks and dirt.
Sometime after burial, one of the girl mummies was struck by lightning, which damaged her left ear and shoulder. But the other two child mummies were undamaged. According to the San Jose Mercury, the second girl mummy has a "cone-shaped" head, which was caused by the Inca practice of binding children's heads at birth to help turn them into the shape of a mountain.
The burial platform itself was also major discovery. It contained over 30 gold, silver, and shell statues (ranging from 2 to 7 inches tall); half of the statues were dressed in clothes. The site also included pottery (some containing food), fabrics woven from alpaca, and some clothing (such as moccasins).
4. The Llullaillaco mummies have revealed a new surprise: at least one of them has (at least) one living relative.
Researchers, lead by team leader Johan Reinhard, have conducted DNA tests on the three mummies. This DNA was matched to DNA taken from 19 people who live in the town of Cabanaconde in Peru's Colca Valley. These individuals had given DNA samples a few years earlier to see if they might be related to the most famous mountaintop mummy, Juanita the Ice Maiden. None matched--but when researched compared their DNA to that of the Llullaillaco mummies, they hit the genetic jackpot.
One of the mummified girls and a man now living near Washington D.C. were a "near perfect" match. Scientists believe that they shared a common ancestor--perhaps 100 years before the girl was sacrificed.
Where to see them
Only a few mountain top mummies appear to be on exhibit. Presently, Juanita is on display at the Museo Santuarios de Alturain Arequipa, Peru. An eight- or nine-year-old boy sacrificed on Cerro El Plomo in Chile is exhibited at the National Museum of Natural History in Santiago. And "Los niños dormidos de Llullaillaco" ("The sleeping children of Llullaillaco) are exhibited at the Museo de Arqueología de Alta Montaña in Salta, Argentina.
One of the best books about Incan mummies is Johan Reinhard's Ice Maiden: Inca Mummies, Mountain Gods, and Sacred Sites in the Andes which covers his discoery of Juanita and other mountaintop mummies in South America. He gives a good, solid background to the topic. Highly recommended!
The Mummy Congress by Heather Pringle devotes part of a chapter to a discussion of the Inca royal mummies and their ultimate destruction. Another chapter discusses Juanita, her discovery, and her political preservation. Well worth reading!
Mummies, Disease and Ancient Cultures by Eve and Aidan Cockburn and Theodore Reyman hasan excellent chapter on "The Mummies of Peru" by James Vreeland Jr. Many b&w photos. As a comprehensive survey of what's happening around the world of mummies, the book is indispensible. 402 pages. Highly recommended.
The Incas and Their Ancestors: The Archaeology of Peru by Michael Moseley is an excellent book about the Incas. Though it doesn't focus primarily on mummies, it contains pertinent information about the mummies of Incan rulers and mountain sacrifices, for example. Moseley also covers Paracas and Chinchorro mummies as well.
Bodies from the Ice: Melting Glaciers and the Recovery of the Past by James M. Deem contains a chapter on the mountaintop sacrifices made by the Inca, including Juanita and the sleeping children of Llullaillaco.