* Presidios. The Spanish also built a number of presidios, or forts, in California. These presidios were used to protect the missions and the Spanish settlers. The remains of some of these presidios are still visible today.
* Artifacts. Archaeologists have found a variety of artifacts that show that Spanish explorers reached California. These artifacts include Spanish coins, pottery, tools, and weapons.
* Documents. There are also a number of documents that show that Spanish explorers reached California. These documents include diaries, letters, and maps.