Why did the Templars mark this mysterious spot on the map?

The hermitage of San Bartolomé, a 12th-century chapel in the Rio dos Lobos Canyon, was built by the Templars in a very specific spot.

By connecting the main Templar strongholds in the Iberian Peninsula, you can draw a cross on the map with the San Bartolomé hermitage right in the centre, at the very heart of an area with an ancient mystical history. But could the symbolism inside the chapel also link the location to the mythical Ark of the Covenant?