The best single lens for travel photography is the Nikon Z 24-120mm S. This lens provides an impressive range of focal lengths, making it perfect for those seeking a single high-quality lens for all their travel needs. It is also compact and user-friendly, making it easy to carry around while traveling. Another great option is the Sony FE 24-240mm OSS, which is an ultrawide travel camera lens that is easily handholdable. The Canon EF 24-105mm IS II USM and the Tamron 18-400mm Di II VC HLD are also popular choices for travel photography due to their versatility and range. Ultimately, the best single lens for travel photography will depend on personal preferences and needs, but these lenses are all excellent options to consider.