Formed : 26 January 1972
Headquarters: Painavu
Second largest District of Kerala

• Anamudi(2695 m) is the highest peak in Kerala. It is situated in the Kuttampuzha Panchayat of Adimali Block, Devikulam taluk.
• The Pambar River originates in the Anaimudi Hills.

• Vagamon is a hill station in Idukki.
• Eravikulam National Park is the first national park in kerala. It became a National Park in 1978.
• Pampadum Shola National Park is the smallest national park in Kerala. Established in 2003.
• Periyar National Park established in 1982. Founded as Nellikkampatty Game Reserve in 1934. It is notable as an elephant reserve and a tiger reserve. 

• Kumali is known as 'the Gateway of Thekkady'.

• The Mullaperiyar dam was built in 1895, is the first dam in Kerala. Located on the Cardamom Hills of Idukki District.
• The Mullaperiyar dam is constructed at the confluence of the Periyar and Mullayar.

• Pallivasal electric project commissioned in 1940 is the first Hydro-electric project in Kerala-Muthirampuzha river.
• The second Hydroelectric project in Kerala is Chenkulam (1954)- Muthirampuzha.

• Idukki dam is situated between Kuravan and Kurathi hills.
• The Idukki dam is the first Indian arch dam, build across the Periyar river.
• Munnar means "three rivers",referring to its location at the confluence of the Mudhirapuzha, Nallathanni and Kundaly rivers.
• Moolamattom Power Station the largest underground power station in Kerala.
• Cheruthony is the largest and highest gravity dam in Kerala.

• Periyar (244 km) is the longest river in Kerala. It originates from Sivagiri Hills.
• Periyar National Park was established in 1982.

• Chinnar is a rain shadow region of Kerala.
• Chinnar Wildlife Sanctuary is located in Devikulam taluk in the Idukki district.
• Many rare species of animals including Grizzled giant squirrels, Indian star tortoise are spotted in Chinnar.
• Kurinjimala sanctuary in Idukki gets its name from the word Kurinjimala which means a mountain where Kurinji blooms.

• The Ponmudi Dam is a masonry gravity dam in Idukki.
• The Mankulam grama panchayat in Idukki is the first Panchayat in Kerala to sell electricity.

• Idukki District leads in the production of tea, cardamom, pepper, vanilla, cloves.
• Important Waterfalls in Idukki- Thommankkuthu, Keezharkuth, Cheeyappara, Lakkom, Thoovanam 

• Mattuppetty Indo-Swiss Project is a livestock project of Kerala started in 1963.
• Chitra Pournami festival of Mangala Devi Kannagi temple is famous. It is located on the border of Tamil Nadu and Kerala.

• Idukki district is the first district in India to get connected with super-fast broad band system as part of Digital India.
• Idamalakkudi is the first tribal panchayath of Kerala.
• Kumily is the largest Gram Panchayat in Kerala
• Ramakkalmedu wind farm is in Idukki.
• Thodupuzha is the only muncipality in Idukki district.

• Udambannoor in Idukki is the first Bio-village in Kerala.
• Vandanmedu in Idukki is the largest producer of cardamom in the world.
• Cardamom Research Station, Pampadumpara was established in the year 1956 under the State Department of Agriculture, Government of Kerala.
• Indian Cardamom Research Institute (ICRI) was established in 1978 as the research wing of Spices Board India, at Myladumpara.