This paper presents the design and implementation of a forest fire monitoring and warning system based on long range (LoRa) technology, a novel ultra-low power consumption and long-range wireless communication technology for remote sensing applications. The proposed system includes a wireless sensor network  that  records  environmental  parameters  such  as  temperature, humidity,  wind  speed,  and  carbon  dioxide  (CO 2 )  concentration  in  the  air, as well as taking infrared photos. The data collected at each sensor node will be transmitted to the gateway via LoRa wireless transmission. Data will be collected,  processed,  and  uploaded  to  a  cloud  database  at  the  gateway. An  Android  smartphone  application  that  allows  anyone  to  easily  view  the recorded data has been developed. When a fire is detected, the system will sound  a  siren  and  send  a  warning  message  to  the  responsible  personnel, instructing them to take appropriate action. Experiments in Tram Chim Park, Vietnam,  have  been  conducted  to  verify  and  evaluate  the operation  of  the system.