A "must-see" list for visitors to Punta Cana and Casa de Campo would have to include the following.

Indigenous Eyes Ecological Park and Preserve

Covering more than six square miles of coastal and inland habitat, it allows visitors to see many native birds, plants, and animals. There is a lagoon, underground river, and iguana farm, as well as a classic petting zoo and educational visitor's center. A good idea for those with children or anyone who wants to understand the need to preserve large swaths of the area even as it becomes more and more popular with travelers around the globe.

Bavaro Runners

A unique way to meet true Dominican families and to experience unusually themed trips. Whether you want to visit a cigar maker, ride horses on the beach, or see an old sugar plantation, this firm provides the organized tours.

Marinarium 

This is close to Cabeza de Toro and is a very eco-friendly way to enjoy snorkeling in an offshore pool.

Parque Nacional del Este 

Stretching more than 300km and including islands and mainland regions, it is sanctuary to 500+ native species. Guided tours may be available or a roadway along the coast provides vistas.

Cueva Fun Fun

This is an organization that takes groups on guided tours of the large cave system in the area. Guests enjoy horseback riding, hiking in the forests and then they enter into the caves where swimming is enjoyed in an underground river.

Altos de Chavon

Not far from Casa de Campo, this artist's village has a museum, amphitheater, artisan's shops, restaurants, and more.

Isla Saona

A boat trip to Isla Saona (near the Punta Cana/Cap Cana area) and or a boat trip to Isla Catalina (near Casa de Campo); their beaches are spectacular and the islands are rich in wildlife with many species of birds and tropical marine fish. Both islands are nature reserve and considered part of the Parque Nacional del Este.

Any of these attractions would provide visitors with a unique experience apart from the many excellent amenities at their villa and resort. Naturally, the simplest list of things you must do when in this part of the Dominican Republic would read water sports, golfing, beach going, horseback riding, shopping, and dining. There are some parks outside of the resorts that offer opportunities for rafting, swimming with dolphins, and other adventures, but few can compare to the peace and relaxation available on resort grounds.

If you do spend time in Santo Domingo before heading east to the Punta Cana area, an ideal itinerary would include the Colonial Zone (as this is part of the UNESCO site). Stops at the most familiar monuments are a must, and would include the Calle de las Damas, the Columbus Lighthouse, the Columbus Alcazar, and the Cathedral of Santa Maria la Menor.

Visitors should also visit the three lagoons known as Los Tres Ojos, which are part of the Parque Mirador del Este. This would allow a wonderful walking tour of the city's finest neighborhood and provide ample opportunities for a bit of sightseeing, shopping, and dining without any need to head into the more bustling parts of the modern city.

A day outside of the Punta Cana or Casa de Campo area would serve as a good reminder of the wonderfully pristine beauty that defines these locales. Returning after a day in the city would probably stimulate the visitor to more deeply enjoy the natural surroundings, including the beaches that are such a popular draw