The results of the 2017 National Geographic Travel Photographer of the Year Contest are now in, with grand-prize winner Sergio Tapiro Velasco set to receive a 10-day trip for two to the Galápagos Archipelago with National Geographic Expeditions, for his incredible shot of lightning striking the erupting Colima Volcano in Mexico. National Geographic was kind enough to allow me to share the winners and honorable mentions with you here, from three categories: Nature, Cities, and People. The photos and captions were written by the photographers, and lightly edited for style.