*sorry, apparently I can not fix the typo in the title* Those things are awesome! With the right Pantheon you can start them with producing 2 gold, 2 food, 2 science and 3 culture. They literally saved my last game, when due to WC embargos, I wasn't able to trade with ANYONE (CS or Civs, both passed) during a huge part of the game. By the time I got the WC leadership, it was already endgame (got diplomatic victory), but those camps put me ahead in science and culture the entire game. Of couse I used my trade routes internally to grow the population, and ended up with a capital size 50 or so and a few VERY big cities.