Seven tubes meet in a center where there was, or there is water in the underground on Mars. I believe that facts are constructions artificially, how the waterfalls or the pyramids
or el bunker
http://ovnidigiart.blogspot.com/2008/03/la-fortaleza-en-marte-bunker-on-mars.html
The structure of the arcs of these tubes is in all Pipelines found so far in a rectangular shape. These tubes are constructed in rectangular arched along their paths.
Only the diameters of these tubes are constantly changing. But at the end of his trajectory are shrinking as a root of a tree. They are seeking water or bringing water to places like oil in a pipeline. 
Figure 2: the seven tubes on the circle (c) set out a connection pipe to a tank. The no. 1, chest tube that is partially visible, the rest of it is underground (in Mars soil land has no other name). The numbers 2-7 mark the tubes
Greetings Josef Bauer
