Limes Saxoniae was a big wall that was built a long time ago to protect a place called Saxony. It was like a big fence that went all around the place to keep people out. The wall was made of stones and it had towers on it so guards could see if any bad guys were coming. The people who built the wall didn't want any bad guys to come in and hurt the people who lived in Saxony. Now, the wall is really old and it's not used anymore, but sometimes people visit it to learn about what it was used for.