The Nilgiris district (Tamil: நீலகிரி மாவட்டம்) is one of the 38 districts in the southern Indian state of Tamil Nadu. Nilgiri (English: Blue Mountains) is the name given to a range of mountains spread across the borders among the states of Tamil Nadu, Karnataka and Kerala. The Nilgiri Hills are part of a larger mountain chain known as the Western Ghats. Their highest point is the mountain of Doddabetta, height 2,637 m. The district is contained mainly within the Nilgiri Mountains range. The administrative headquarters is located at Ooty (Ootacamud or Udhagamandalam). The district is bounded by Malappuram district of Kerala to the west, Coimbatore and Palakkad to the south, Erode to the east, and Chamarajnagar district of Karnataka and Wayanad district of Kerala to the north. As it is located at the junction of three states, namely, Tamil Nadu, Kerala, and Karnataka, significant Malayali and Kannadiga populations reside in the district. Nilgiris district is known for natural mines of Gold, which is also seen in the other parts of Nilgiri Biosphere Reserve extended in the neighbouring states of Karnataka and Kerala too.

Nilgiris district நீலகிரி மாவட்டம் View of the Nilgiris near Ooty

Sim's Park is in Coonoor, The Nilgiris, Tamil Nadu. It is an important tourist place to visit in Coonoor, at a height of 1780 meters above mean sea level. Here the maximum temperature goes up to 28 degree Celsius and the minimum falls to 5 °C. The average rain fall of this garden is 150 cm. It extends over an area of 12 hectares of undulating land and possesses a number of natural advantages.