Bromo Tengger Semeru National Park has sub-montane, montane and sub-alpine ecosystem types, with big trees that are hundreds of years old.
Among the plants that exist in the Park are jamuju (Podocarpus imbricatus), cemara gunung (Casuarina sp.), edelweiss (Anaphalis javanica), various species of orchid, and rare species of grass (Styphelia pungieus).
In addition, there are about 137 species of bird, 22 species of mammal, and four species of reptile in this Park.
Some of the endangered and protected animal species inhabiting the Park are the marbled cat (Pardofelis marmorata), deer (Cervus timorensis russa), long-tailed macaque (Macaca fascicularis), barking deer (Muntiacus muntjak muntjak), red junglefowl (Gallus gallus), panther (Panthera pardus), Asian wild dog (Cuon alpinus javanicus) and various species of bird such as the besra sparrow hawk (Accipiter virgatus virgatus), crested serpent eagle (Spilornis cheela bido), rhinoceros hornbill (Buceros rhinoceros silvestris), black drongo (Dicrurus macrocercus), brahminy kite (Haliastur indus), and ducks that live on the Ranu Pani, Ranu Regulo and Ranu Kombolo Lakes.
Bromo Tengger Semeru National Park is the only conservation area in Indonesia that has a sand 'sea'. This unique feature covers a total area of 5,250 hectares at an altitude of about 2,100 m asl.
Beneath the sand sea, seven eruption centres have been found along two intersecting lines, one from east to west and the other from northeast to southwest. From this northeast-southwest line emerged Mt. Bromo, an active volcano which intermittently emits smoke and ash, and is an ever-present threat to the lives of some 3,500 people living below.
The crater of Mt. Bromo has a diameter of about 800 metres from north to south and 600 metres from east to west. Most of the area within a radius of 4 km from the crater centre is considered hazardous.
The Tenggerese people that live around the Park are indigenous to the area and adhere to ancient Hindu beliefs. According to legend, the ancestors of the tribe were members of the Majapahit kingdom who went into exile. Strangely, despite being aware of the potential dangers of Mt. Bromo, the local people seem unafraid. The same goes for the visitors who come to the Park in great numbers, particularly around the time of the "Upacara Kasodo". The Upacara Kasodo (Kasodo Ceremony) is held every year (December/January) at the full moon. Through this ceremony, the Tenggerese invoke the blessings of the deities to ensure an abundant harvest, to be spared from calamity and to be cured of various diseases. To earn such blessings, they climb down the sides of the crater to catch the offerings thrown into the crater by other members of the community above. The scramble for possession of the 'sacrifices' is at once a gripping, but terrifying sight: it is not uncommon for some of the participants to tumble down to the crater's floor.
Cemorolawang: one of entrance gates through which visitors pass to see the expanse of the sand sea and Bromo's crater from a distance; camping is possible here.
Tengger Sand Sea and Mt. Bromo: horse riding; climbing up concrete steps to the rim of Mt. Bromo's crater, and witnessing the sunrise.
Pananjakan: viewing a magnificent panorama of Mt. Bromo, Mt. Batok, and Mt. Semeru.
Ranu Pani, Ranu Regulo, Ranu Kumbolo and Mt. Semeru. These cool, misty lakes (" 2,200 m asl.) are a frequent stopover on the way to Mt. Semeru's peak (3,676 m asl.).
Ranu Darungan Lake: camping and observing animals and plants; incredible views.
Best time of year to visit: June to October, and December to January.