Aberdare National Park history in brief
The Aberdare range carries two names. Joseph Thomson named it in 1884 after Lord Aberdare, then president of the Royal Geographical Society. Nyandarua is the alternative name of the mountains. The national park was founded on 18 May 1950 and is managed by the Kenya Wildlife Service (KWS). It covers 765.7 km², or about 766 km².
The park is only part of the story. The range is also a water catchment, a place of the Mau Mau war and the setting of a famous royal stay. If you want to see the park as it is today, compare Aberdare day trips and safari tours and read the history on the way.
Our pick: a hiking tour with historic sites
This three-day walking tour passes historic sites in the park, with Kimathi Post on the route.
Hand-picked tours, booked through GetYourGuide. Prices are indicative starting prices in US dollars (as of October 2026). Tap a tour for live availability and the current price in your currency.
Aberdare tours and day trips
See the park today on a guided safari or day trip, with live prices and availability.
Key dates in the history of the Aberdares
From the name of the range to the fence.
1884: the range is named
Joseph Thomson gave the range the name Aberdare. The alternative name Nyandarua is also used.
1932: Treetops opens
Treetops dates its opening to 1932. Princess Elizabeth stayed there on 5 and 6 February 1952.
Treetops and The Ark →1950: the national park
The park was founded on 18 May 1950. Today's area is not automatically the same as the area at the founding.
1952 to 1963: the Emergency
The forests of the range were a place of the Mau Mau war during the Emergency, from October 1952 to December 1963.
Mau Mau in the Aberdares →2009 and 2010: the fence
Building of the electric fence ended in August 2009. The ceremonial opening followed on 12 March 2010.
2024: Treetops reopens
A celebration in August 2024 marked the reopening of Treetops after the closure that began in 2021.
The fence around the Aberdares
The Rhino Ark fence runs for 400 to 410 km. It was built from 1989 to August 2009 and completed on 28 August 2009. KWS, the Kenya Forest Service and the neighbouring communities worked on it together with Rhino Ark. Its purpose is to protect forest and wildlife and to reduce conflict between animals and farms along the edge.
Building and opening are two different events, which is why the fence has two dates, 2009 and 2010. The fence line and the park boundary are not the same line, so do not use the fence to measure the park. Inside the park, keep to the wildlife rules, including the 20 m distance.
Water for Nairobi
The mountains do more than shelter animals.
The Aberdares are a catchment area. Nairobi's water supply draws on the Sasumua and Ndakaini reservoirs, which are fed from this range. That is a main reason why the forest and its fence matter far beyond the park.
| Topic | Date or figure | Note |
|---|---|---|
| Range named | 1884 | Joseph Thomson, for Lord Aberdare |
| Park founded | 18 May 1950 | 765.7 km² today |
| Fence built | 1989 to August 2009 | 400 to 410 km |
| Fence opened | 12 March 2010 | Ceremonial opening |
| Treetops reopened | August 2024 | After the closure of 2021 |
For most visitors, the three dates that matter are 1950 for the park, 1952 for the royal stay and the start of the Emergency, and 2009 to 2010 for the fence.
The royal stay of 1952 at Treetops
Two places in the story.
Princess Elizabeth stayed at Treetops on 5 and 6 February 1952, and her father, George VI, died during those days. She heard the news either at Treetops or at Sagana Lodge near Kiganjo, and the place is not settled. The stay at Treetops and the moment she heard of her father's death are not the same thing, and the coronation came later.
Treetops is open again today. Access to the rhino sanctuary area follows its own rules, which the Treetops page explains. The Ark, another lodge in the park, offers viewing at a lit waterhole and salt lick.
Other parks have their own stories. For another Kenyan park, the history of Nairobi National Park has its own guide.
Aberdare history: frequently asked questions
When was Aberdare National Park founded?
On 18 May 1950. It is managed by the Kenya Wildlife Service and covers about 766 km².
Why is it called Aberdare?
Joseph Thomson named the range in 1884 after Lord Aberdare, then president of the Royal Geographical Society. Nyandarua is the alternative name.
How long is the Aberdare fence?
400 to 410 km. It was built from 1989 to August 2009 and opened in a ceremony on 12 March 2010.
Did Queen Elizabeth hear of her accession at Treetops?
The place is not settled: it was either Treetops or Sagana Lodge near Kiganjo. She stayed at Treetops on 5 and 6 February 1952.
Why is the Aberdare range important for Nairobi?
The Aberdares are a catchment area. Nairobi's water supply draws on the Sasumua and Ndakaini reservoirs, which are fed from this range.