Tourists at a scenic observation tower in a wildlife reserve were treated to an unforgettable sight when a mother bear lay down to nurse her three cubs just metres away.

Delightful footage shows the black creature reclining to feed her babies while remaining alert, frequently looking around to assess her surroundings.

The rare scene was captured in the Kronotsky Nature Reserve, a protected area on Russia's far eastern Kamchatka Peninsula.

The bear kept her head raised, guarding her young as they fed.

State inspector Liana Varavskaya said on Tuesday, August 5, that while all tourists hope to witness a nursing bear, the group that day was especially fortunate as the animal settled almost directly beneath their observation point.