Original source code, written in Fortran, from the very first text adventure game in the videogames history (1976). / I collected some other goodies from around the internet (maps, walkthroughs…). Even executables for Windows & Mac OS !
https://github.com/davepinch/pinchy.cc/blob/master/content/topics/gaming/games/pdp-10/colossal-cave-adventure/source-code/github.com.md