A general review of cosmic energetic gamma particles is given. A discussion on the subject starting with the discovery of the PeV gamma rays by Sammorski and Stamm, passing to the super-nova SN1987A explosion when several groups waited for high energy gamma particles but none has come so far up to the measurements of TeV gamma incoming from the Crab Nebula. The discussion in this paper is a by product of the cosmic ray research done in the Chacaltaya Cosmic Rays Observatory in the past few years. A brief description of the facilities on Mount Chacaltaya (5,200 m a.s.l.) is also given.