Often times, archaeological sites are found by artifacts lying on the ground. When artifacts are found in a test hole, they are counted and their location is written down. Areas where lots of artifacts are found may be considered an archaeological site. If archaeologists went out and just began to dig big holes, it would be very hard to remember exactly where each artifact was found. Square holes, or excavation units , are each given a label.
Every artifact is labeled with the name of the square in which it was found.
This helps us remember its location, or context , after it is removed from the ground. A map is made of each unit so that the maps can be put together like a puzzle. It is important to remember that when dirt and artifacts are removed from a site, they can never be put back exactly as they were found. This is why careful excavation and good maps and records are so important. Over time, soil naturally builds up layer after layer as people live in an area.