Was there any special celebrations to honor poseidon?

Yes, ancient Greeks held various celebrations to honor Poseidon, the god of the sea. One of the most notable was the Panhellenic festival called the "Isthmian Games," which included athletic competitions, music, and poetry contests, held every two years near Corinth. Additionally, rituals and sacrifices were performed at coastal temples, such as the Temple of Poseidon at Sounion, to seek his favor for safe voyages and bountiful catches. These celebrations reflected the importance of the sea in Greek culture and the reverence for Poseidon's power.