Engaruka Basin Geosite
Engaruka is located at the foot of the Manyara–Natron rift scarp at about 1000 m a.s.l, and about 43 km north of Mto wa Mbu and almost the same distance south of Lake Natron, Northern Tanzania. There are several geo-tourism tour packages sites such as Engaruka Juu, Chini, Oldonyo Lengai, and several craters. These geo-tourism sites are potential for aesthetic, scientific and education value.
Engaruka Juu: Ancient Engaruka Village
Engaruka Juu has a complex of late Iron Age farming settlement covering an area of about 25 Km2(Robertshaw, 1986). The farming communities at Engaruka depended on an irrigation system (Sutton, 1986). Remains of terraced irrigated fields, stone/lined irrigation furrows, houses, stone circles and probably graves are found at the site (Plate 42, 43 and 44), which are unique in size and preservation. The first archaeological investigation of the area started in 1900s. Nonetheless Engaruka ancient village has extensively researched by Sutton (1974, Sutton, 1978, Sutton, 1986, Sutton, 2000) and others. Recent surveys of the habitation platforms indicate that what was thought to be seven villages might in fact have been one continuous settlement, broken only by obstacles such as rivers and gullies.
Reconstructions based on settlements indicate that the past population was much greater than the 7,000-12,000 people (Laulumaa, 2006). The ancient land-use system at Engaruka Juu consists of an extensive pattern of terraces, stone-lined fields, cairns, stone circles and irrigation canals. These were constructed using soil, reinforced with cores of stones and boulders. Given the size and elaborated nature of the arable fields it is evident that agriculture was the dominant activity. Regarding crops cultivated, only sorghum has been confirmed (Sassoon, 1967), and it is likely that this was the dominant crop, supplemented with a wide variety of other food crops. Some stone circles have been interpreted as cattle pens (Sutton, 1986), and it is highly probable that livestock, being of immense cultural and economic value, was an important, supplementary asset.
Plate 42: Part of the ancient irrigation system at Engaruka Juu
Plate 43: Remains of stone house having two rooms
Plate 44: Well-preserved circular stones interpreted as cattle pens
Researches have indicated that the formerly irrigated and now abandoned fields are located on and below alluvial fans deposited where five rivers from Mt Lolmalasin flow over the escarpment. Today, only Engaruka River is permanent, while the other rivers carry water only during heavy rains. However, the extent and configuration of terraces and canals indicate that all rivers once were used for irrigation and it is thus evidencing that the water flow in the now dry rivers was greater some- time in the past. Features built during wetter periods may, of course, have been used also during drier periods, but it is unlikely that much effort would have been invested if the water supply were not more reliable than at present.
According to the most recent archaeological findings the settlements of ancient Engaruka were occupied until the early 1800s. The ancient system then fell into decline, and Engaruka was perhaps even abandoned completely for some time. Although there have been a lot of explanation on the downfall of ancient Engaruka but the more plausible cause might be the extreme drought due to climate change, catastrophic events and change in the livelihood strategies for coping with environmental change, subjected the fall of ancient Engaruka.
Engaruka Chini: Pillars of Ashes
These are volcanic pillars forming unique features on the wide flat area. Small volcanic eruption of the now dormant volcanic mountains near Engaruka resulted to volcanic mudflow on termite mounds and other obstacles which finally drying up as pillars remnants of the standing features on the flow direction (Plate 45). These pillars have extended in the area of almost five hectares creating a uniqueness of its kind especially because the pillars just stand on top of the surface having no roots underground.
Plate 45: Pillars of ashes of Engaruka Chini
Both Engaruka Juu and Chini are potential for geo-tourism. Nonetheless tourists on their way to Lake Natron and craters discussed in the next section they bypass Engaruka sites because either tour and safari operators do not know the potential attractiveness of these sites or they cannot interpret them. Posting a guide who can present and interpret these sites to the public will attract tourists and tour and safari operators to stop at Engaruka.
There are six several volcanic craters around this area. Of the six, two of them are bigger than than the rest. One of the biggest crater is on the ground level with the diameter of more than 700 meter square (Plate 46-47). According to the local people who were our key informants the crater is known in Kiswahili as “Shimo la mungu” (god’s pit). These were formed after the violent volcanic explosion and when the eruption was over, the volcano collapses in on its empty vacant magma chamber and forms a volcanic crater.
Inside the biggest crater, domesticated animals were seen eating pastures. These craters are known to the tour operators who bring tourists in the area. Also Maasai women wait for the tourists around the crater to sell their traditional souvenirs. This diversifies their livelihood economy and improves their income.
Plate 46: Section of one of the Crater in Engaruka
Plate 47: Showing “Shimo la mungu” crater occuring on the ground level