Simiyu Region in the context of "Serengeti National Park"

Arusha Region (Swahili: Mkoa wa Arusha) is one of Tanzania's 31 administrative regions and is located in the northeast of the country. The region's capital and largest city is the city of Arusha. The region is bordered by Kajiado County and Narok County in Kenya to the north, the Kilimanjaro Region to the east, the Manyara and Singida Regions to the south, and the Mara and Simiyu regions to the west. Arusha Region is home to Ngorongoro Conservation Area, a UNESCO World Heritage Site. The region is comparable in size to the combined land and water areas of the state of Maryland in the United States.

Arusha Region is a tourist destination in Africa and is the hub of the northern Tanzania safari circuit. The national parks and nature reserves in this region include Ngorongoro Conservation Area, Arusha National Park, the Loliondo Game Controlled Area, and part of Lake Manyara National Park. Remains of 600-year-old stone structures are found at Engaruka, just off the dirt road between Mto wa Mbu and Lake Natron. With a HDI of 0.721, Arusha is among the most developed regions of Tanzania being Tanzania's top 3 most resourceful region.

Mara Region (Mkoa wa Mara in Swahili) is one of Tanzania's 31 administrative regions. The region covers an area of 21,760 km (8,400 sq mi). The region is comparable in size to the combined land area of the nation state of El Salvador. The neighboring regions are Mwanza Region and Simiyu Region (to the south), Arusha Region (to the southeast), and Kagera Region (across Lake Victoria). The Mara Region borders Kenya (to the northeast).The regional capital is the municipality of Musoma. Mara Region is known for being the home of Serengeti National Park, a UNESCO World Heritage site and also the birth place of Tanzania's founding father Julius Nyerere. Under British colonial occupation, the Mara Region was a district called the Lake Province, which became the Lake Region after independence in 1961.

Manyara Region (Mkoa wa Manyara in Swahili) is one of Tanzania's 31 administrative regions. The regional capital is the town of Babati. According to the 2012 national census, the region had a population of 1,425,131, which was lower than the pre-census projection of 1,497,555. For 2002–2012, the region's 3.2 percent average annual population growth rate was tied for the third highest in the country. It was also the 22nd most densely populated region with 32 people per square kilometre.

Lake Manyara is in the northern part of the region. It is bordered to the north by the Arusha Region, to the northeast by the Kilimanjaro Region, to the east by the Tanga Region, to the south by the Dodoma Region, to the southeast by the Morogoro Region, to the southwest by the Singida Region, and to the northwest by the Simiyu Region. The highest mountain in the Manyara Region is Mount Hanang.

Karatu District (Wilaya ya Karatu, in Swahili) is one of seven districts of the Arusha Region of Tanzania. The district is bordered to the north by the Ngorongoro District and to the west by the Meatu District in the Simiyu Region. The district is bordered to the east by the Monduli District, and to the south and southeast by the Mbulu District and the Babati District. The district covers an area of 3,207 km (1,238 sq mi). The district is comparable in size to the land area of Samoa. The district has a max elevation of 1,739 m (5,705 ft) on Oldeani Peak. Predominantly settled by Iraqw, Karatu district is home to the hunter-gatherer community of the Hadza people. Also Karatu is known agriculturally as the onion capital of Tanzania. The district capital is the town of Karatu. According to the 2022 census, the population of the district was 280,454.

Singida Region (Mkoa wa Singida in Swahili) is one of Tanzania's 31 administrative regions. It covers a land area of 49,340 km (19,050 sq mi), comparable in size to the nation of Slovakia. The region is bordered to the north by Shinyanga Region, Simiyu Region and Arusha Region, to the northeast by Manyara Region, to the east by Dodoma Region, to the southeast by Iringa Region, to the southwest by Mbeya Region and to the west by Tabora Region. The regional capital is the municipality of Singida. According to the 2022 national census, the region had a population of 2,008,058.