Kalkar is a municipality in the district of Kleve, in North Rhine-Westphalia, Germany. It is located near the Rhine, approx. 10 km south-east of Cleves. The most famous building of Kalkar is its church St. Nicolai, which has one of the most significant sacral inventory from the late Middle Ages in Europe.
Kalkar was founded by Dirk VI of Cleves in 1230 and received city rights in 1242. It was one of the seven "capitals" of Cleves (called Kleve), until the line of the Duchy of Cleves died out in 1609, whereupon the city went over to the Margraviate of Brandenburg. Marie of Burgundy, Duchess of Cleves retired to Monreberg castle in Kalkar, where she founded a Dominican convent in 1455. Under her influence the city bloomed and artists were attracted to the favorable climate for cultural investment. She died at Monreberg castle in 1463.
Between 1957 and 1991, West Germany, Belgium and the Netherlands pursued an ambitious plan for a fast breeder nuclear reactor, the a 300-megawatt prototype reactor, SNR-300, near Kalkar. Construction of the SNR-300 began in April 1973. In the wake of large anti-nuclear protests at Wyhl and Brokdorf, demonstrations against the SNR-300 reactor escalated in the mid-1970s. A large demonstration in September 1977 involved a "massive police operation that included the complete closure of autobahns in northern Germany and identity checks of almost 150,000 people".
Construction of the Kalkar reactor was completed in the middle of 1985, but a new state government was clearly against the project, and opposition mounted following the Chernobyl disaster in April 1986. In March 1991, the German federal government said that the SNR-300 would not be put into operation. The project costs, originally estimated at $150 to $200 million, escalated to a final cost of about $4 billion.