text: The first reason why this is just a natural landform is because it can also happen on earth. For example, this can happen upon natural sources. Such eratation and it can just be a mesa. Another example is, "Scientists figured it was just another Martian mesa, common enough round Cydonia"(2). If this is common than most likely it wouldn't be made by any alien. My last example for this is, most landforms have ways it can look. The landforms can happen anywhere and that wouldnt mean it was caused by an alien. If something like this happened on earth most people would think it was caused by natural thigs like the weather.