Caltiki, the Immortal Monster

A team of archaeologists led by Professor John Fielding (John Merivale, Circus of Horrors) descends on the ruins of an ancient Mayan city to investigate the mysterious disappearance of its inhabitants. However, the luckless explorers get more than they bargained for when their investigation of a sacrificial pool awakens the monster that dwells beneath its waters - the fearsome and malevolent god Caltiki.