Kashi is also called as Varanasi, and it gets its name by being the meeting point of two rivers: Varuna and Asi.
Kashi is actually not outside but within us. The Ajna chakra (the sixth metaphysical centre of energy in the human body) is the meeting point of the Ida, the Pingala and the Sushumna Naadis (energy channels in the human body).

(freed from the duality of the material world to unite with the divine).
You should not understand this to mean that everyone necessarily has to go to Kashi only to die and attain liberation.
Where is Kashi actually? It is the region in the middle of the eyebrows on the forehead, the region of the Ajna Chakra – which is the meeting point of Varuna (represented by the Ida Naadi) and Asi (represented by the Pingala Naadi). So if one’s prana is steadily established in this region at the time of death, then one attains liberation. This is what is truly conveyed by these sayings.

There is another meaning attached to the city of Kashi.

Kashi means one that is overflowing with knowledge. In the ancient days, it was a great seat of knowledge and learning. In those days, there were scholars in every street of this great city who would go about debating and explaining the meanings of the scriptures. People would discuss knowledge and scriptures.

The city of Kashi in those days was renowned for overflowing with knowledge and intellectual discourses in every nook and corner.

It was said that the city was so enriched with knowledge that even a Parrot and a Mynah(bird) would discuss knowledge. So one who sits in the company of such wise and enlightened ones surely attains liberation just by listening to the knowledge.

Kashi has been held in great importance through the ages because it was always the centre of knowledge and intelligent people. Scholars from all over the country would come to Kashi to search and discuss knowledge in the ancient days, such was its glory. But today you will hardly find 15-20 such people who have this genuine depth and interest in knowledge. Such is the unfortunate state of the city today. I feel sad to see this.
When I was a young boy, I remember that there were so many reputed scholars there. Today there are very few genuine ones to be found.