National Geographic is inviting photographers from around the world to enter the 2015 National Geographic Traveler Photo Contest. The grand-prize winner will receive an eight-day National Geographic Photo Expedition to Costa Rica and the Panama Canal.The deadline for submissions is Tuesday, June 30, at 12 p.m. EDT. Eligible contestants can visit their website to submit photographs in any or all of four categories: Travel Portraits, Outdoor Scenes, Sense of Place and Spontaneous Moments. The entry fee is $15 (USD) per photo, and there is no limit to the number of submissions per entrant. Here is a selection of this year's entries: