Athens, Greece, became the newest "sister city" to New York as their two mayors signed a symbolic agreement.

The symbolic familial relationship between the two historic cities was sealed Thursday by Mayor Eric Adams and his Athenian counterpart, Mayor Kostas Bakoyannis.

Together, they signed a sister city agreement that promises to expand cooperation in tourism, environmental protection, technology and cultural matters.

“New York City has always been inspired by Athens’ example — a place where people of different backgrounds come together to seek a better future for themselves and their fellow citizens," Adams said in a statement.

"Athens' example" — for those who nodded off during history class — goes back thousands of years.

The Ancient Greek city-state of the same name in the 6th century B.C. developed a system of government near and dear to Americans: democracy.

The legacy of early democracy was evoked by Bakoyannis as he hailed the sister city agreement.

“The ‘City of Wisdom’ and the ‘Big Apple’ are joining forces," he said in a statement. "To move in tandem, forwards and upwards.

"Our democratic values of tolerance, equality, and individual freedom are our common starting point. Our citizens and their ideals bring us together, from the Parthenon to the Statue of Liberty and from Astoria to Koukaki."

Adams signed the agreement with Bakoyannis in Athens City Hall, officials said. He visited Greece to participate in the international 2022 Mayors Summit Against Antisemitism.