English: An extremely rare discovery, this is a wonderful 1693 double hemisphere map of the world in two panels. Both of these maps were drawn and engraved by the German Enlightenment era polymath Johann Zahn for his pseudo-scientific opus Mundus Mirabili , or the “Marvelous World.” This, Zahn’s cartographic masterpiece, is a smorgasbord of carto-curiosity featuring such unusual elements as an insular California, the Great Lakes rendered as a single body of water open to the west, the strait of Anian far to the north, El Dorado or Manoa on the shores of the mythical Lake Parima, the legendary Lago de los Xarayes, an erroneously oriented Caspian Sea, a speculative Ptolemaic mapping of the sources of the Nile, an incomplete Australia, and the five great rivers of southeast Asia radiating from a single apocryphal lake , among others. Our survey of this map will begin with North America on the western hemisphere sheet. North America is rendered according to the common 17th century Dutch conception and owes much to the work of Nicholas Visscher whose maps played a significant role in promoting the “California as an Island” hypothesis. The concept of an insular California first appeared as a work of fiction in Garci Rodriguez de Montalvo's c. 1510 romance Las Sergas de Esplandian, where he writes Know, that on the right hand of the Indies there is an island called California very close to the side of the Terrestrial Paradise; and it is peopled by black women, without any man among them, for they live in the manner of Amazons. Baja California was subsequently discovered in 1533 by Fortun Ximenez, who had been sent to the area by Hernan Cortez. When Cortez himself traveled to Baja, he must have had Montalvo's novel in mind, for he immediately claimed the Island of California for the Spanish King. By the late 16th and early 17th century ample evidence had been amassed, through explorations of the region by Francisco de Ulloa, Hernando de Alarcon, and others, that California was in fact a peninsula. However, by this time other factors were in play. Francis Drake had sailed north and claimed New Albion near modern day Washington or Vancouver for England. The Spanish thus needed to promote Cortez's claim on the Island of California to preempt English claims on the western coast of North America. The significant influence of the Spanish crown on European cartographers caused a major resurgence of the Insular California theory. About half a century after this map was drawn Eusebio Kino, a Jesuit missionary, published his own 1705 account of travels overland from Mexico to California, establishing conclusively the peninsularity of California. Zahn’s rendering of the Great Lakes as a single body of water open to the west is of particular interest and is the most ephemeral element of this map, being updated in most subsequent maps to reflect ongoing European exploration of the region. At first glance Zahn’s great inland sea appears uncannily like Verazanno’s Sea, a 16th century speculative body of water extending to the Pacific through the center of North America, which was no doubt a direct influence on the water form established here. Subsequent mapping of this region would see this great inland sea replaced by more contemporary rendering of the Great Lakes taken from the explorations of La Salle, Hennepin, and others. North of insular California we find the land of Anian, separated from the North American mainland by a narrow strait. Anian is generally considered to be an undiscovered land or strait in the extreme northwestern part of America. The earliest known reference to Anian is in the narratives of Marco Polo, who describes it as “East of India”. In many early maps Anian appears as an imaginary proto-Bearing Strait, the Strait of Anian, separating Asia from America. Zahn’s treatment of Anian is unusual.