Aḍhāī-dvīpa is a Hindi term meaning ‘Two and A Half Continents’. The Two and A Half Continents where human beings live is frequently depicted in maps or colourful diagrams. This part of the Middle World is the only part of the universe where people can be born so it is also known as ‘the World of Humans’ – manuṣya-loka.

The Middle World – madhya-loka – is one of three worlds in the Jain conception of the universe. The Middle World in Jain tradition is formed of concentric rings of differing size. Every other ring is a continent, which is surrounded by a ring of ocean. These alternate rings of continents and oceans number 90 in all but the Two and A Half Continents is the main focus of many works of Jain cosmology.

Starting from the centre, the Two and A Half Continents consists of:

1. the central continent, called Jambū-dvīpa
2. the first ocean, known as Lavaṇa-samudra – ‘Salt Ocean’
3. the second continent, Dhātakīkhaṇḍa
4. the second ocean, called Kālodadhi – ‘Black Water Ocean’
5. half of the third continent known as Puṣkara-dvīpa. 

Mount Meru is the centre of the universe in Jain cosmology, at the heart of the central continent of Jambū-dvīpa. 

Jain cosmology is complex. Human beings live in the Middle World, which is the smallest of the three worlds that make up world space – loka-ākāśa. In world space all the souls live in the different body-forms they take according to their rebirths, in the various worlds. Outside world space is the non‑world space – aloka-ākāśa – which is endless. However, the Middle World is the most important area from the spiritual point of view because it is the only part where human beings can live.

Jains cannot advance spiritually without understanding and meditating upon cosmological theories so understanding them is crucial. Certain key religious concepts run through these theories. These include the notion of a physical soul shedding karma by moving through the cycle of rebirth to eventual omniscience and liberation, along with the cyclical nature of time, the interconnectedness of the universe, and the importance of symmetry, repetition and balance.