The following text is for questions 14 to 17.

Kutai National Park

    Kutai National Park is a lowland tropical forest in East Kalimantan, with a total land area of about 198,629 hectares. 
    Biodiversity and vegetation make Kutai National Park a great ecotourism destination for local as well as foreign nature lovers and researchers. Mangroves, freshwater Swamp forest, Dipterocarpaceae, ironwood, ebony trees and orchids species can be found in the park. As well as a potential wealth of flora, Kutai National Park also has a grand diversity of fauna. Primate groups like orangutan, gibbon, proboscis monkeys and long-tailed macaques and other animals like Kalimantan rhinos, deer, sun bear, crocodiles and hundreds species of birds live in tpe park area.
    Kutai National Park has several tourist attractions such as Sangkima, Prevab and Kaba Bay. Sangkima and Prevab are the most visited. Sangkima is located near the highway of Bontang-Sangatta. Visitors can either see ironwood trees with a diameter of 2.47 meters or observe the animals in the wildlife. Visitors can also test their courage by crossing a suspension bridge made of ironwood.
    Prevab, approximately a 25-minute boat ride up the Sangatta River, is one of the important orangutan research centers. There are many students and researchers conducting researches in this area. Another attraction is Kaba Bay, which lies between the cities of Bontang and Sangatta, reachable by speedboat. There are various colored corals and a variety of fish in the bluish green water. Settlements of Bajau people are found around the pristine coastal forests of Kaba Bay.

Adopted from: http://www.newsoftourism.com/kutai-nationalpark-ecotourism-tours/; http://www.dephut.go.id/INFORMASI/TN%20INDO-ENGLISH/kutai_NP.htm (October 20, 2018)

Where can visitors visit the orangutan research center?