ΟΑΚΑ, or the Olympic Athletic Center of Athens, is a multi-sport complex located in Athens, Greece. It was built for the 2004 Summer Olympics and serves as a venue for various sports events, including athletics, basketball, and volleyball. The center features several facilities, including a main stadium, an indoor arena, and an aquatic center. The main stadium, known as the Athens Olympic Stadium, has a seating capacity of around 69,000 spectators. It is home to the A.E.K. F.C., a prominent football club in Greece. ΟΑΚΑ also hosts concerts and cultural events, making it a significant landmark in the city.