ARCA or Arca may refer to:

Ronald Eldon Wyatt (1933 – August 4, 1999) was an adventurer and former nurse anaesthetist noted for advocating the Durupınar site as the site of Noah's Ark, among other Bible-related pseudoarchaeology. His claims were dismissed by scientists, historians, biblical scholars, and even by leaders in his own Seventh-day Adventist Church, but his work continues to have a following among some fundamentalists and evangelicals.

Wyatt was as a nurse-anesthetist when in 1960 he saw a picture in Life Magazine of the Durupınar site, a boat-like shape on a mountain near Mount Ararat. The resulting widespread speculation in evangelical Christian circles that this might be Noah's Ark started Wyatt on his career as an amateur archaeologist. From 1977 until his death in 1999 he made over one hundred trips to the Middle East, his interests widening to take in a wide variety of references from the Old and New Testaments.

By the time of his death on August 4, 1999, his claimed discoveries included:

While Wyatt won a devoted following from the ranks of fundamentalist Christians seeking tangible evidence of the literal truth of the Bible, his credibility was disputed, often bitterly, by professional archaeologists and biblical scholars. The Garden Tomb Association of Jerusalem state in a letter they issue to visitors on request: