Clifford's Tower, York, England
This is all that remains of a castle that was first constructed, in wooden form, by William the Conqueror in 1086. In 1190, about 150 Jews took refuge here when local citizens began to riot against the Jewish population. Many of the Jews committed suicide to avoid capture. Many others died after the building was set on fire. The rest perished at the hands of the mob.
The destroyed castle was replaced with another wooden structure, but it collapsed in a storm in the 1200s. In 1270, Henry III ordered the construction of a stone castle on this site.
The castle is named after Roger de Clifford, who was hanged here for treason in 1322.