The Sultanpur National Park is known for:

Birdwatching
Tiger safes
Ancient ruins
Hilly landscapes

The Sultanpur National Park is known for birdwatching. It is a bird sanctuary located in the Gurgaon district of Haryana, India. The park is spread over an area of 1,000 hectares and is home to a variety of birds, including flamingos, pelicans, and herons. The park is also a popular tourist destination and offers a variety of activities, such as birdwatching, boating, and picnicking.

The other options are incorrect. Tiger safes are not a thing. Ancient ruins are not found in the Sultanpur National Park. Hilly landscapes are not a characteristic of the park.