Unmanned Aerial Vehicle (UAV) technology integrated with Light Detection and Ranging (LiDAR) (UAV-LiDAR) has emerged as a powerful tool for generating highly detailed terrain maps by a huge point cloud. This makes it a suitable method for creating terrain surfaces for building information modeling (BIM)-based infrastructure design. However, the quality of UAV-LiDAR-derived terrain maps is influenced by various factors, including the UAV's flight altitude. This study focuses on investigating the impact of flight altitude on the accuracy of UAV-LiDAR terrain maps. Experimental work was conducted in a hilly region with flight altitudes varying from 80, 120, and 150 m using a DJI Matrice M300 RTK (M300) UAV equipped with a DJI Zenmuse L1 LiDAR sensor and a UAV speed of 6 m/s. The results demonstrate a clear correlation between terrain map elevation accuracy and flight altitude. Lower flight altitudes lead to the generation of more accurate terrain maps.