PHOTOS: Extreme world slackliners

The sky is not the limit for these impressive slackliners, who have taken the extreme sport to another level. From walking a highline higher than the Eiffel Tower to balancing above the clouds in Portugal, these impressive photos give us a snapshot of the sights these slackliners witness from above. The various photographers who took these pictures were all visiting Europe when they captured the amazing images. (Caters News)