Delhi is both a city and a state, which has the full name National Capital Territory (NCT) of Delhi. The capital of India is New Delhi, which is located on both sides of the Yamuna river. Located in Northern India dry winter humid subtropical climate, with monsoon arriving at the end of June. However, it borders at a hot semi-arid climate, and so the city once had 100 stepwells, ancient cisterns used to provide drinking water. There are lowlands, the flood plains of the Yamuna River, provide fertile alluvial soil suitable for agriculture but are prone to recurrent floods. The Delhi Ridge originates from the Aravalli Range in the south and encircles the west, northeast, and northwest parts of the city. The plains are around 240 m asl, while the hills reach a height of 318 m asl.