 Complete the following phrase:  Ancient kingdoms that existed in the Kathmandu valley are found to have made use of some clever technologies in numerous areas such as architecture, agriculture, civil engineering, water management, etc. The Gopals and Abhirs, who ruled the valley up until 1000 BC, used temporary materials for construction such as bamboo, hay, timber, etc. The Kirat period 700 BC  110 AD employed the technology of brick firing as well as produced quality woolen shawls. Similarly, stupas, idols, canals, self-recharging ponds, reservoirs, etc., constructed during the Lichhavi era 110 AD  879 AD are intact to this day, which manifests the ingenuity of the traditional architecture. Moreover, the Malla period 1200 AD  1768 AD further saw an impressive growth in architecture, comparable with the advanced contemporary nations. An archetypal example of Malla architecture is Nyatapola, a five-storied, 30-meter tall temple in Bhaktapur, which has strangely survived at least four major earthquakes, including the 