This remembers the murders of people with handicaps and mental illnesses under the Nazi regime at the NS-Tötungsanstalt Hadamar.

[3] Hadamar lies 7 km north of Limburg between Cologne and Frankfurt am Main on the southern edge of the Westerwald at elevations from 120 to 390 m above sea level.

One of the oldest witnesses to the Hadamar region's settlement is the cist (see also Megaliths) stemming from the Wartberg culture, and therefore some 5,000 years old, in Hadamar-Niederzeuzheim.

On the spot where now stands the Renaissance palace on the banks of the Elbbach, Cistercian monks from Eberbach Abbey in the Rheingau worked a model farm in the 13th century which Count Emich von Nassau-Hadamar bought in 1320 and converted into a moated castle.

He had the old moated castle expanded as his residence into a Renaissance palace, and he laid out the Baroque new town's streets in a grid pattern with broad marketplaces and public fountains.

The Prince called the Franciscans to town, supported the building of the monastery with endowments and saw to the establishment of the Society of Jesus in Hadamar in 1630.

Johann Ludwig von Nassau-Hadamar managed to bring his lordly domain some importance when the Emperor named him Commissioner-General of the negotiations surrounding the Peace of Westphalia, which eventually put an end to the Thirty Years' War.

After several conversions, Johann Ludwig became Catholic again in 1629 and arranged for Jesuits to live in Hadamar who instituted a Gymnasium in 1652.

Prince Johann Ludwig is the namesake of the comprehensive school that has grown out of this Jesuit Gymnasium, and which still exists today in Hadamar.

The Corrigendenanstalt, the forerunner of today's Centre for Social Psychiatry, was built in 1883 beside the former Franciscan monastery on the Mönchberg.

The institution served as a workhouse for interning and reeducating vagrants in the Regierungsbezirk of Wiesbaden and had 236 places for men and 80 for women.

In the neighbouring former monastery at the same time, an institution for rural paupers (Landarme) from Hadamar and the outlying countryside was founded that was less strictly run and seldom had more than a dozen inmates.

In Nazi Germany, beginning in 1941 at the NS-Tötungsanstalt Hadamar as it is nowadays called in German (literally: "Hadamar Nazi Killing Facility"), the then state health and care facility on the Mönchberg, at least 14,494 handicapped or mentally ill people, along with those known as "Half-Jews" under the Nuremberg Laws and Ostarbeiter ("Eastern workers") were murdered.

Among these are the Fürstenschloss (princely residence) with its old stone bridge, the Liebfrauenkirche (church) with a bell from the time of the Thirty Years' War, the Stadtkirche ("Town Church") with the old Franciscan friary, the former Jesuit house on the Mönchberg, the renovated "Old Town Hall", the synagogue, the historic marketplaces, and some old timber-frame houses.