Question: Iwama dojo was built by what martial artist who is often referred to as the founder, Kaiso, or Great Teacher?
Context: Doshin So (宗道臣 , Sō Dōshin ) (born Michiomi Nakano (中野道臣 , Nakano Michiomi ) ), was a Japanese soldier and martial artist.  He is most known as the creator and founder of Shorinji Kempo and the doctrine Kongo Zen (金剛禅 , Kongō Zen ) .  Practitioners of Shorinji Kempo refer to him as "Kaiso, "Japanese for "the founder". Ansei Ueshiro (宇江城 安盛 , Ueshiro Ansei , April 20, 1933 - May 7th, 2002) was an influential Okinawan martial artist, who was the nephew of Ankichi Arakaki, the chief instructor at the original Nagamine Dojo in Okinawa and the composer of Fukyugata Sandan kata.  Born in Kin, Okinawa, Ueshiro relocated to the United States in 1962 at the request of founder Shōshin Nagamine of Matsubayashi Shōrin-ryū, under whom he had studied, for the purpose of spreading the martial art.  He founded Shorin-Ryu Karate USA and, according to that organization's official website, "was one of the first Oriental martial artists to bring karate" to the US. Morihei Ueshiba (植芝 盛平 , Ueshiba Morihei , December 14, 1883 – April 26, 1969) was a martial artist and founder of the Japanese martial art of Aikido.  He is often referred to as "the founder" "Kaiso" (開祖 ) or "Ōsensei" (大先生/翁先生 ) , "Great Teacher". Iwama dojo is a dojo built by the founder of aikido, Morihei Ueshiba, who lived there from 1942 until his death in 1969.  It is located in the former town of Iwama and became an important historical location for the development of aikido and "a Mecca to the aikido community."  This dojo is also where Morihiro Saito, one of the founder's closest students, learned and taught aikido from 1946 until 2002 developing what is often referred to as the Iwama Style. Hiroshi Isoyama (磯山博 , Isoyama Hiroshi ) is a Japanese teacher of the martial art of aikido.  He began training in the Iwama Dojo at the age of 12 as a direct student of the founder of aikido, Morihei Ueshiba in June 1949.  He currently holds the rank of 8th dan shihan in the Aikikai and is that organization's Technical Councillor.  Isoyama was made the acting head of the Iwama dojo on behalf of Ueshiba Moriteru following the passing of Morihiro Saito.  He currently remains as Executive Advisor and senior instructor of that dojo. Yutaka Kurita (栗田 豊 , Kurita Yutaka ) (born 20 April 1940 in Tokyo, Japan) was one of the last live-in students ("uchideshi") of the founder of aikido, Morihei Ueshiba.  He entered the Aikikai Hombu Dojo in 1956 and after a year as a regular aikido student was accepted as an "uchideshi" by Ueshiba and went with him to live, work and train at the Iwama dojo.  He received his 3rd dan (sandan) directly from Ueshiba and served him as his assistant/attendant, scribe, "uke", and assisted in instructing when people came from Tokyo to Iwama to study aikido. Hitohiro Saito (斎藤 仁弘 "Saitō Hitohiro", born 12 February 1957 in Iwama) is an aikido instructor and founding headmaster of Iwama Shin-Shin Aiki Shuren-kai.  Hitohiro is the son of Morihiro Saito.  At age of seven, he started to learn aikido from Morihei Ueshiba, the founder of aikido, who cared for him as a grandson.  .  After Ueshiba died in 1969, he continued his practice with his father.  The younger Saito became an official instructor of the Iwama dojo in 1986 and remained so until 2004 when he separated from the Aikikai organization and formed his own group.  Since 2009 he is also identified as Hitohira (仁平) Saito. Robert Bowles is an American Karate teacher and the founder of the International Shuri-Ryu Association.  Bowles is a member of the United States Karate Alliance Hall Of Fame.  Hanshi Robert Bowles, has studied martial arts for over 35 years.  He holds a 10th Degree black belt in Shuri-ryū karate, and is one of the late Robert Trias' eight Chief instructors of the Shuri-ryū system.  He is the founder and director of the International Shuri-ryū Association.  He began his karate training in Phoenix, Arizona under Grand Master Robert Trias.  Karate began as a hobby which ultimately changed the direction of his life.  During the 1960s he trained in the honbu dojo which became his primary focus.  Local tournaments lead to national competitions and soon Bowles had established himself as one of the top competitors in the country.  Grand Master Trias personally awarded him the Trias International Award, which is given to the most spirited competitors in the world.  However, karate was still relatively new in most parts of the country.  In light of the fact that Grand Master Trias opened the first karate school in the United States (1946) and was a recognized authority in the field of martial arts, a steady stream of requests for information flowed into the honbu dojo.  Bowles was sent by Grand Master Trias as an ambassador of Shuri-ryū to teach and promote Shuri-ryū across the country.  He was personally appointed by Grand Master Trias as Chief Instructor of the Shuri-ryū system and given the lifelong commission to uphold the standards of the Shuri-ryū karate-do. Iwama Style Aikido is the style of aikido that was taught at Iwama dojo (in Iwama) by the founder of aikido, Morihei Ueshiba, and especially the lineage passed on through Morihiro Saito, a close disciple who was given responsibility over Iwama dojo by Ueshiba. Avi Nardia (Hebrew: אבי נרדיה‎ ‎ ) is a Martial Artist and he is the Founder of KAPAP Israeli Krav Maga, ], a hand to hand combat system that includes elements of Lotar (Lohama Be terror - Anti Terror units style), ], Krav (IDF - Israeli Army Hand to Hand Program), Hagana Atzmit (Self Defense - Defensive Tactic - Israeli Operational Police Academy Hand to Hand program.)  His wide martial arts experiences include: holding Black Belts in several Traditional Martial Arts styles with life-long training in many leading martial arts styles and Budo such as Brazilian Jiu-Jitsu instructor with a Black Belt under Machado RCJ, Kendo (6th Dan with Study under Kubo Akira), Iaido (5th Dan) and Jodo (5th Dan) teacher, Kyudo (4th Dan) teacher, Judo (3rd Dan) and Japanese Jiu-Jitsu instructor (7th Dan Most Senior Teacher with Kyoshi rank under Patrick McCarthy), Karate KU and Goju Ryu (Under Leon Pantanowitz, and Tadano Tomiyaki & Patrick McCarthy 6th Dan) Thai Box instructor.  Avi also spent 8 years living and studying Martial Arts such as Uchi Deshi (living student) and devoted his life to the study of Martial Arts as his words reflect here - "Always student, sometimes teacher" and has tried to roll his life-experiences and knowledge into Reality Training as his words reflect here - "Better to be a student of reality than a master of Illusion."  Adding to his varied study is also sports study: Avi is certified in sport study as an Olympic fencing coach, Athletic trainer and Sport Therapist and Fitness coach and also has different sports certifications including rappelling.
Answer: Morihei Ueshiba