Terra Natura is Benidorm's main wildlife park, set inland from the beach resort and organised around themed habitats. It is a family attraction first, with animal exhibits, educational shows, and enough space to make a full half-day away from the seafront.
For independent travellers it will not outrank the old town, beaches, or nearby mountains, but for families it is one of Benidorm's more practical non-beach options. Combine it with the adjacent water-park offerings only if you want a very full theme-park day.