There are four types of temple buildings: temples (unlocked with Free Spirit), forest temples (cheaper to build, unlocked with Spiritualism), mountain temples (unlocked with Meditation), and water temples (unlocked with Aquatism).
Temples are fantastic investments in games where points matter, provided you build them early enough. Temples upgrade every three turns after being built, which increases their value to your score. Temples start out at 100 points and max out at 400 points 12 turns later.