When you travel aboard National Geographic Endurance or National Geographic Resolution, you can end an invigorating day of exploration with a soak in an infinity-edged hot tub, followed by a night under the polar sky in a geodesic glass igloo.

Founder and CEO Sven Lindblad has long been fascinated by igloos and when he saw some in Finland made of clear materials that allowed people to gaze up at the northern lights, he knew he had to replicate that experience on our new ships. Today, they are the only igloos you can find at sea.

Both the igloos and the hot tubs have enthralled our guests and they're sharing their enthusiasm on Instagram. Here are a few of our favorite posts.