Kasi is amongst the holy spots for visit by the Hindus.  It is believed that a visit to Kasi ensures liberation & hence pious Hindus seek a visit during their lifetime.  This is the location of the Benares Hindu University, the place of learning of several aspects of Hindu culture.  The Lord himself has declared this spot as his Royal residence.  Goddess Parvathi's mother felt ashamed that her son-in-law had no decent dwelling.  To please Parvathi Devi,  Siva asked Nikumbha to provide him with a dwelling place at Kasi.

On the request of Nikumbha, Aunikumbha a brahmin made Divodas construct a temple for the Lord here.  The pleased Lord granted boons to all his devotees.  But Divodas was not blessed with a son.  The angered Divodas demolished the structure.  Nikubha cursed that the area would be devoid of people.  When the place was emptied Lord Siva once again took residence here permanently.  The Lord along with Parvathi Devi once again started blessing his devotees with wonderful boons. 

Parvathi Devi was so pleased that she offered food (annam) to one and all and hence is worshipped as Annapoorani.  The Lord himself is seen with a bowl in his hands asking for annam from the seated Devi at the Devi's shrine adajacent to Viswanathar's shrine.  This is considered to be one of the 52 Sakthipeedams (the place where Parvathi's left hand fell, when her corpse was cut by Mahavishnu's sudarsana chakram).

The Siva lingam is placed in a square shaped brass plated pit.  Devotees are permitted to offer  worship such as abhishekam with holy ganga water, garlanding the Lord, karpoora aarathi, etc. personally to the swaymbhu lingam.
There are several smaller shrines around the main shrine.  The head of each ghat has a Siva linga shrine.  The Lord can be seen placed on a pedestal at every location in the city, even if there is not shrine as such. Behind the temple is situated the temple of Dhundhiraja Ganapathi.