Oakland, California feature the oak and the logo of the East Bay Regional Park District is an oak leaf. The coats-of-arms of Vest-Agder, Norway, and Blekinge, Sweden, feature oak trees. The coat-of-arms of the municipality Eigersund, Norway features an oak leaf. Military Oak leaves are traditionally an important part of German Army regalia. The Nazi party used the traditional German eagle, standing atop of a swastika inside a wreath of oak leaves. It is also known as the Iron Eagle. During the Third Reich of Nazi Germany, oak leaves were used for military valor decoration on the Knights Cross of the Iron Cross. They also symbolize rank in the United States Armed Forces. A gold oak leaf indicates an O-4 (major or lieutenant commander), whereas a silver oak leaf indicates an O-5 (lieutenant colonel or commander). Arrangements of oak leaves, acorns and sprigs indicate different branches of the United States Navy staff corps officers. Oak leaves are embroidered onto the covers (hats) worn by field grade officers and flag officers in the United States armed services. If a member of the United States Army or Air Force earns multiple awards of the same medal, then instead of wearing a ribbon or medal for each award, he or she wears one metal representation of an "oak leaf cluster" attached to the appropriate ribbon for each subsequent award. Political The oak tree is used as a symbol by a number of political parties. It is the symbol of Toryism (on account of the Royal Oak) and the Conservative Party in the United Kingdom, and formerly of the Progressive Democrats in Ireland and the Democrats of the Left in Italy. In the cultural arena, the oakleaf is the symbol of the National Trust (UK), The Woodland Trust, and The Royal Oak Foundation. Religion The prehistoric Indo-European tribes worshiped the oak and connected it with a thunder or lightning god, and this tradition descended to many classical cultures. In Greek mythology, the oak is the tree sacred to Zeus, king of the gods. In Zeus's oracle in Dodona, Epirus, the sacred oak was the centerpiece of the precinct, and the priests would divine the pronouncements of the god by interpreting the rustling of the oak's leaves. Mortals who destroyed such trees were said to be punished by the gods since the ancient Greeks believed beings called hamadryads inhabit them. In Celtic polytheism, the name