instruction: Who built Sigiriya fortress in Sri Lanka?
context: It is likely that the area around Sigiriya may have been inhabited since prehistoric times. There is clear evidence that the many rock shelters and caves in the vicinity were occupied by Buddhist monks and ascetics from as early as the 3rd century BC. The earliest evidence of human habitation at Sigiriya is the Aligala rock shelter to the east of Sigiriya rock, indicating that the area was occupied nearly five thousand years ago during the Mesolithic Period.
  
  Buddhist monastic settlements were established during the 3rd century BC in the western and northern slopes of the boulder-strewn hills surrounding the Sigiriya rock. Several rock shelters or caves were created during this period. These shelters were made under large boulders, with carved drip ledges around the cave mouths. Rock inscriptions are carved near the drip ledges on many of the shelters, recording the donation of the shelters to the Buddhist monastic order as residences. These were made in the period between the 3rd century BCE and the 1st century AD.
  
  In 477 AD, Kashyapa I, the king’s son by a non-royal consort, seized the throne from King Dhatusena, following a coup assisted by Migara, the King’s nephew and army commander. The rightful heir, Moggallana, fearing for his life, fled to South India. Afraid of an attack by Moggallana, Kashyapa moved the capital and his residence from the traditional capital of Anuradhapura to the more secure Sigiriya. During King Kashyapa’s reign (477 to 495 AD), Sigiriya was developed into a complex city and fortress. Most of the elaborate constructions on the rock summit and around it, including defensive structures, palaces, and gardens, date from this period.
response: King Kashyapa developed Sigiriya city and fortress.