Because these places are quie inaccessible, my son takes tourists ( mostly younger people) to some of these places. He's taken tour groups to Socotra, Turkmenistan, and Saudi Arabia. Actually the crater is something I'd like to see as part of his 5 'Stan tour. He's currently in Syria. His tour company is called Young Pioneer Tours if you're interested in going to any of these places. ( Shameless plug, but no affiliate link)