Not aliens, but UFO's. I went clubbing with 4 friends of mine and when we finished we went to porto rafti beach which was closeby to chill there a bit. My friend suddenly started screaming and pointing up trying to show us something. We obviously thought he was drunk or something but after 20 seconds all 5 of us saw it as well. It was 2 weird looking objects flying at a very high altitude at pretty high speeds (more than fighter aircrafts) and they kept the same distance from each other throughout the whole minute that we could see them, after approx a minute, they dissapeared. This happened at around 4AM and it seemed pretty weird although there could be some logical explanation ... I dunno :/