Donna Nook is a military bombing range (they suspend activities for the seal season!) in North Lincolnshire, and the seals will return to exactly the same spot (within a metre or so) year after year. 

Seals come ashore during November to give birth and breed ready for the following year. The pups stay with the mother for 5-6 weeks during which time they pile on the weight at an astonishing rate due to the fatty content of the mothers milk. Once weaned, the mother, having mated again, leaves the pups to look after themselves and they return to the sea.