Surely a colony on the moon should come first. It's a viable destination and within a short rescue time. Maybe not as glamourous but a similar test of technology at lower cost and we could look up at night and see morse code signals etc. It will give people a greater connection plus delay times between transmissions are lower. Just to look up and see a reflective glint from the base would be amazing.
Going to mars is like running before you can walk. The next logical step is a permanent base on the moon. What we learn on the moon will make Mars far easier as the next step. Also if there are valuable resources on the moon its viable to send them to earth.
These holes/pits make living on the moon more viable. Ideal for habitats under the edges and a greenhouse environment in the middle.
http://www.theverge.com/2014/7/18/5915743/nasa-moons-underground-caves-could-house-astronauts
