All the -stans

"-stan" is the Farsi or Urdu suffix that means roughly "place of", or "place where one stands".  There are presently 8 countries that end with this suffix, all in central Asia.  All but two were part of the Soviet Union until its breakup.  Pakistan (and its relative, Bangladesh, which was once called "East Pakistan") were the Muslim areas of Britain's India colonies at the time of partition in 1947.  Afghanistan managed some level of independence through the "Great Game".  Dagestan is still a Russian subject.

Afghanistan  is a country in south central Asia, between Iran and Pakistan
Dagestan is a subject country of Russia in south western Asia, east of Chechnya and Georgia, and north of Azerbaijan, along the western shore of the Caspian Sea
Kazakhstan is a country in central Asia, north of India the Caspian Sea, and south of Russia
Kyrgyzstan  is a country in south central Asia, along part of the border between Kazakhstan and India
Pakistan is  is a country in south central Asia, between Pakistan and India
Tajikistan  is a country in south central Asia, between Kyrgystan, Afghanistan and Uzbekistan
Turkmenistan is a country in south central Asia, between Uzbekistan and Iran, on the southeastern Caspian Sea
Uzbekistan is a country in south central Asia, between Kazakhstan and Turkmenistan

In addition there were many regions that are now part of a larger country that were "stan". Nuristan is a province in eastern Afghanistan.  It was once called "Kafiristan" and Kipling wrote about it in "The Man Who Would Be King".  Balochistan is a region which lies in Iran, Afghanistan and Pakistan.   It's very arid, and is the home of a great deal of insurgency.

The Registan is the public square at the center of Samarkand, Uzbekistan

The Rigestan Desert is in southeastern Afghanistan

Rigestan is also a town in southwestern Iran