Co-op City, one of the largest cooperative housing developments in the world, is now 50 years old.

About 500 guests were expected to pile into the Marina del Rey Monday evening to celebrate 50 years of what the Riverbay Corporation says has been clean, affordable housing.

The Riverbay Corporation, which manages Co-op City, also recognized some of the first Co-op City residents who moved into their homes when the Throgs Neck development first opened.

It honored Fred Clarke, whose brother received a key to the city when their family first moved into Building 1. The Clarke family was one of the first African-American families in what was a heavily white area at the time.

The city broke ground on the major project in 1966, and it saw its first tenants in December 1968. The land that 35 skyrises sit on used to be an amusement park.

Organizers also honored Amalgamated Bank which is representing the Amalgamated Clothing Workers Credit Union, the main sponsor of Co-op City and Rep. Eliot Engel, an original shareholder.