Many of the upright 7.5-foot-high (2.3-meter-high) plastic foam dominoes carried messages, including “We are one people.” The 1,000 dominoes stretching for 1.5 kilometers (1 mile) will be toppled Monday.

German Chancellor Angela Merkel, herself a resident of East Germany when the wall fell, said that it was a day that “changed the lives of many people including me.”

“It is particularly nice for us to be able to celebrate this day with our European neighbors,” Merkel said. “We Germans will not forget our neighbors and allies who made the path to German reunification possible.”