Juanjui is the capital of Mariscal Cáceres Province (the largest in the region) in the south of San Martin region in northern Peru.
Since the airport is not in use, the only way to get into Juanjui is by road. Your best option is to fly from Lima to Tarapoto and from Tarapoto take a collective taxi to Juanjui. Both LAN Peru, Star Peru and TACA Peru fly to Tarapoto from Lima. A collective taxi know as colectivos will cost 20 soles per person and an express taxi know as expreso will cost 80. The average time from Tarapoto to Juanjui is 2 hours.