The Zverinetsky Cross
In the early 20th century, archaeologists discovered the ancient Zverinetsky Monastery in a cave complex beneath Kiev, in modern-day Ukraine. As they explored the monastery church, which was established before the 13th-century Mongol invasion, they found this Cross carved into one of the walls. It depicts the Cross "planted upon the earth"; the Greek letters surrounding it form the Christogram "Jesus Christ is victorious". This same Christogram frequently appears on Russian and Greek prosphora seals, with a simple two-bar Cross.