The picture, taken by photographer David Gubler, shows a passenger train on the limestone Wiesen Viaduct of the Rhaetian Railway in the canton of Graubünden.
It was judged the best photo from more than 365,000 submissions in the competition, organizers announced on Tuesday.
Regarded as the biggest of its kind in the world, the contest is put together by Wikimedia, the organization behind Wikipedia, the free online encyclopaedia.
Winners were selected from freely licensed photos of monuments used to illustrate Wiki articles.
The snap by Gubler was praised by Wiki for representing a “nice harmony between monument, human and nature, while the red train draws attention to the middle of the picture”.
The submissions were judged by a jury for technical quality, originality and “usefulness of the image for Wikipedia”.
He won a trip to Wikimania, Wikipedia’s annual conference, set for London next summer, including travel and accommodation.
The Wiesen Viaduct, 88 metres high and 204 metres long, was completed in 1909 for the Davos-Filisur railway and later served as the inspiration for a 1926 painting by German expressionist artist Ernst Ludwig Kirchner.
It is the largest stone bridge on the Rhaetian Railway, according to Wikipedia.
For more information on Wiki Loves Monuments, check here.