10 amazing photos of nature taken at the perfect moment

The 2015 National Geographic Traveler Photo Contest is nearing its conclusion. Judging by the entries National Geographic is showing off, the competition looks tough.

In last year's contest, there were more than 18,000 entries to the contest. Photos are divided into four categories: travel portraits, outdoor scenes, sense of place, and spontaneous moments.

Entries for this year's contest are being accepted until June 30th. If you think you've got what it takes, enter here.

The grand prize winner gets an eight-day National Geographic Photo Expedition: Costa Rica and the Panama Canal with airfare for two.

To celebrate the end of the contest, National Geographic has shared some of its favorite entries from the "Spontaneous Moments" category with us here.