The stone cross at Leiasundet , also known as the Kvitsøykrossen , is Kvitsøy's most famous ancient monument . It is 3.9 meters high, and one of the tallest of its kind in the country. The cross is 1.87 meters wide and is made of slate. At the foot, the cross stem is 48 cm wide and 14 cm thick. The cross arms taper towards the center, while the stem is wide and straight. The cross is described as well-proportioned and neatly carved. It is without inscriptions. There are no graves or burial mounds at the site and the cross is not believed to have been erected as a memorial to a deceased person. On some older maps, the island is called Kreutz-Eiland, which suggests the late Middle Ages. The island is called Krossøy and may have previously been referred to as Hvitingsøy.  Approximately 100 meters from the cross are ruins of a Klemens church, probably from the early 12th century.