An ancient village very close to Raajgeer in Bihaar. It was situated some 90 Kms in South-East from Patanaa; and 11 Kms in North from Raajgeer. It was established and developed by Kumaar Gupt I or II. It developed into a city of international importance, because by 500 AD, it had become a great learning center for Hindu and Buddhists. Students came from all over the world. Among the famous students were two Chinese students - Huen-Tsaang and I-Tsing in 7th century AD.  It continued to be famous from the 9th century AD to 12th century AD. Its students used to spread Buddhism outside India.

According to a Tibetan source, 5 great Mahaa Vihaar stood out - (1) Vikramshilaa - the premier university of the ear; (2) Naalandaa;  (3) Som Pur;  (4) Odantpuraa;  and (5) Jaggadal

Buildings
It was built in a planned way and its architecture was a unique specimen of art. Its whole compound was surrounded by a great wall which had only one gate to enter. Many statues of Buddha and Mahaaveer were there. Till now only 13 Math have been found in the excavation, but there is a possibility to get more. These Math are over one storey high and had a stone bed for sleeping. Holes in the walls were there to keep books and lamps etc. In the courtyard of each Math, there was a well. Many gardens and lakes have also been found here in its compound. The University had 7 large halls and over 300 classrooms.

Its library alone was housed in three buildings as high as 9 floors - Ratn Ranjak (Delightful lf Jewels), Ratnodadhi (Ocean of Jewels) and Ratna Saagar (Sea of Jewels). Ratnodadhi housed many hand-written rare manuscripts. Chinese travelers took many manuscripts from them with them. It housed more than 300,000 books. It was also known as Dharm Gunj (Mountain of Truth); or Dharm Ganj (treasury of Truth).

Teachers and Students
This University had three kinds of teachers who were divided under First, Second, and Third category according to their ability. Some of the famous teachers were Sheel Bhadra, Dharmapaal, Chandrapaal, Gunamiti and Sthiramiti. An ancient Shlok says that one astronomer Aaryabhat was also a teacher there. His three books are known - Dash Geetikaa, Aaryabhateeya and Tantra. Aaryabhat Siddhaant is also said to be written by him. Its only 34 Shlok are available today. Here the founder of Mahaa Yaan, Naagaarjun, Vasubandhu, Asang and Dharmakeerti's works were taught in detail. Ved, Vedaant, Saankhya, grammar, philosophy, surgery, astrology, Yog, and medicine were also taught here.

The University at any time had at least  3,000 students. Many international students were also there from China, Tibbat, Greece and Persia. Some scholars have estimated this number to be closer to 10,000 and 2,000 teachers. No tuition fee was charged. It was a fully residential University. Every student was provided with hostel, food and other necessities of life, free.

Admission
To get admitted in this University was very difficult. Admission was strict and was based on a screening test of scholarship. One had to pass three tests before getting admission. To have graduated from Naalandaa University was a declaration of the highest academy achievement in those days.

It is tragic that such a great institution was systematically destroyed by foreign non-Hindu, non-Buddhist invaders in the 11th century AD. (read its description below)

Naalandaa has the ruins of the world's oldest universities founded in the 5th century AD on an ancient site of pilgrimage and teaching which had been visited by Buddha and Mahaaveer, who are reputed to have spent 14 years on the site. It is assumed that the Gupt emperors were responsible for Naalandaa's first monasteries. In the 7th century Huaan Tsaang spent 12 years both as a student and a teacher at Naalandaa which once had 3,000 teachers and philosophers. The monks were supported by 200 villages and a library of 9 million manuscripts and restricted with 7, 8 out of 10 applicants failing to gain a place.

Another Chinese scholar came here in 673 AD and recorded the severe lifestyle of the monks. The day was measured by a water clock, and the syllabus involved the study of Buddhist and Braahmanical scriptures, logic, metaphysics, medicine and Sanskrit grammar. Samraat Ashok built a monastery, King Harshvardhan donated a 26 meter high copper image of the Buddha, and Kumaar Gupt endowed a College of Fine Arts. The University flourished until the 12th century, when the Afgaan Bakhtiyaar Khilajee sacked it in 1199, burning and pillaging and driving the surviving the residents into hiding. It was the end of the Buddhism in India, until the modern revival.
[India Handbook, p 835-836]

How Naalandaa University Was Destroyed
According to Wikipedia "Nalanda", Naalandaa university was destroyed 3 times by invaders, but only rebuilt twice. The first time it was destroyed by Hoon under Mihirakul, during the reign of Skand Gupt (455-467 AD), but Skandgupt rebuilt it in a grander way. Second time it was destructed by Gauda in the early 7th century AD. This time Harsh Vardhan (606-648 AD) built it. The third and the final destruction was by Bakhtiyaar Khilajee, a Turk, in 1193 - how he destroyed it, read it below----

It is said that there was a King Bakhtiyaar Khilajee in India. He destroyed it fully by burning it in 1193. He had taken control of some areas governed by Bauddh. Once he fell ill seriously. His Hakeem tried their best to save him, but they could not treat him. Then somebody advised him to consult the Professor of the Department of Aayur Ved, Naalandaa Vishwa Vidyaalaya (University), Rahul Bhadra, and take his treatment. The King did not agree that any Indian could be nore knowledgeable than his own Hakeem; and he should be treated by a Kaafir (means who is not a Muslim). But still he had to invite him to save his own life. He put a condition before Rahul Bhadra that he would not take any of his medicine, and he would have to cure him just like that. If he could not do so, he would be killed.

The Professor came back to his home. he could not sleep the whole night. He continued to think the whole night as what to do of this insane person who does not want to take medicine and wants to be cured at the same time. In the morning he got ready, took a copy of his Quraan and went to the King. He said to him - "If you read its pages from here to here, you will be all right." Bakhtiyaar Khilajee read the pages of those Quraan as instructed and he got cured. he got very angry at this. He was not happy at all at this. He was very angry on his own Hakeem that why they were not so intelligent that they could cure him by reading his own Quraan. How come that this Hindu knew the part of his Quraan to cure him, and his own Hakeem did not know it?

In stead of giving any award or any appreciation, he set the fire in Naalandaa Vishwa Vidyaalaya. All books were also burnt in that fire. There were so many books that they continued to burn for three months. He killed many teachers and Bauddh Bhikshu also. APersian historian Minhaj-i-Siraj, in his chronicle the Tabaquat-I-Nasiri, reported that thousands of monks were burned alive and thousands beheaded as Khilajee tried his best to uproot Buddhism. The gigantic 9-floor library containing millions of manuscripts and books when set to fire burnt for 6 months according to many stories.

Would you like to know how Rahul treated Bakhtiyaar Khilajee?
It was easy. Muslims, while reading their Quraan, turn its pages using their finger smeared with the saliva of their mouth. So Rahul applied some medicine on those particular pages which he asked him to read. As Bakhtiyaar read those pages and turned them with the saliva smeared finger, the medicine went into his stomach and it cured him.