The architecture of Bengal, which comprises the modern country of Bangladesh and the Indian states of West Bengal, Tripura, Assam's Barak Valley and eastern part of Bihar and Jharkhand, has a long and rich history, blending indigenous elements from the Indian subcontinent, with influences from different parts of the world. Bengali architecture includes ancient urban architecture, religious architecture, rural vernacular architecture, colonial townhouses and country houses and modern urban styles. The bungalow style is a notable architectural export of Bengal. The corner towers of Bengali religious buildings were replicated in medieval Southeast Asia. Bengali curved roofs, suitable for the very heavy rains, were adopted into a distinct local style of Indo-Islamic architecture, and used decoratively elsewhere in north India in Mughal architecture.