The next reference, in 1796, describes only ancient mounds. A local landlord who had shifted his residence from Chintapalli to Amaravati laid the foundation of a modern township around the nearby Amareshvara temple, dedicated to Siva, which, dating back to the 10th century, had become an important Hindu place of worship. Many people settled in the area at his invitation and the building activity that ensued caused many of them to help themselves to the abundant supplies of bricks and limestone slabs yielded up by the various mounds that marked the stupa complex. Some elaborate sculptures surfaced and came to the attention of Colonel Colin Mackenzie in 1797. Several European officials then took an interest in collecting sculptures from the site and some attempts were made to excavate the stupa in 1845. More excavations were carried out 1877, 1881 and 1908-09. As a result many of those carvings that had survived were removed and have been preserved in the local Archaeological Museum, the Government Museum in Madras and the British Museum in London, where there is special Amaravati Gallery.
   
Several scholars have identified Amaravati with Dhanyakataka Pal-den Dre-pung in Tibetan, which Tantric scriptures describe as the place of origin of many of the Tantric teachings, in particular the Kalachakra. Several Tibetan pilgrims visited the area in times past, prominent among them Gendun Chophel, the renowned Tibetan scholar, who records that in the late 1930s was very little historical evidence remained.

Amitaba Buddha

The Mahayana sutras appeared between 1st century BCE and 4th CE in Andhradesha. The Perfection of Wisdom Sutras (Prajnaparamita Sutras) and the Vimalakirti Nirdesha Sutra, with its account of the Bodhisattva Vimalakirti leading the life of a layman, appeared in the first two centuries of this period. Around 100 CE, the Sukhavati-vyuha Sutra, with its description of Amitabha’s Pure Land and the possibility of going there, appeared. In approximately 200 CE, the White Lotus Sutra appeared, which emphasized the ability of every sentient being ultimately to become a Buddha, and the way that all the vehicles of the Buddhist path fit together as skilful means. It also has much emphasis on the devotional aspect.

Nagarjunakonda near to Amaravati is associated with the great Indian Buddhist master Nagarjuna, who propounded the Middle Way or Madhyamaka between 150 and 250 CE, based on the Perfection of Wisdom Sutras, which he had recovered from nagas. This was crucial to the emergence of Mahayana Buddhism. Nagarjuna also wrote his celebrated Friendly Letter (Suhrillekha) to one of the local Shatavahana Kings, Gautamiputra. The Mind Only or Chittamatra School developed from the teachings of the Descent into Lanka Sutra (Lankavatara Sutra), which also appeared in Andhradesha around 300 CE.

Literary evidence further reveals that the earliest tantra, the Guhyasamaja Tantra, also emerged in Andhradesha, around the 3rd century CE. The first commentaries to it are attributed to Nagarjuna. Finally, the earliest appearance of Tantra in Andhradesha corresponds to the reference in the Kalachakra texts that Buddha first taught the four classes of Tantra from the four faces of Kalachakra at the Dhanyakataka stupa.

The third sacred Buddhist site referred to in the scriptures as located in this region is Potala, the mountain regarded as the residence of Avalokiteshvara, the Bodhisattva embodying Compassion. However, there is as yet no consensus about its exact location. From: http://www.kalachakra06.com/