According to the Buddhist tradition, Ashoka is said to have visited Khotan in central Asia in 236 B.C. This tradition is based on the historical accounts found in Buddhist texts and inscriptions.

Explanation:

1. Historical Background:
- Ashoka was an Indian emperor of the Maurya dynasty who ruled from 268 to 232 B.C.
- After the bloody Kalinga War, Ashoka embraced Buddhism and became a patron of the religion.
- He actively promoted Buddhism and sent missionaries to spread the teachings of the Buddha.

2. Ashoka's Pilgrimage:
- According to Buddhist texts, Ashoka embarked on a pilgrimage to various Buddhist sites after his conversion to Buddhism.
- The purpose of this pilgrimage was to pay homage to important Buddhist locations and spread the teachings of Buddhism.
- It is believed that Ashoka visited several places associated with the life of the Buddha, including Bodh Gaya, Sarnath, and Kushinagar.

3. Ashoka's Visit to Khotan:
- The Buddhist tradition states that Ashoka also visited Khotan, a region in central Asia, during his pilgrimage.
- Khotan was an important center of Buddhism in the region, and Ashoka is said to have visited the area to propagate the faith.
- The Buddhist texts mention that Ashoka erected numerous stupas and monasteries during his visit to Khotan.

4. Corroborating Evidence:
- The Chinese Buddhist monk Faxian, who traveled extensively in India and central Asia during the 4th century, mentioned Ashoka's visit to Khotan in his travel accounts.
- Faxian's records lend support to the claim that Ashoka indeed visited Khotan.
- Furthermore, archaeological evidence, such as the discovery of Buddhist artifacts and inscriptions, has also been found in the Khotan region, further strengthening the belief in Ashoka's visit.

In conclusion, according to the Buddhist tradition, Ashoka is said to have visited Khotan in central Asia during his pilgrimage. This tradition is supported by historical accounts found in Buddhist texts, the records of Chinese monk Faxian, and archaeological evidence.