there may be specially allotted times for devotees to perform circumambulations (or pradakshina) around the temple. Visitors and worshipers to large Hindu temples may be required to deposit their shoes and other footwear before entering. Where this is expected, the temples provide an area and help staff to store footwear. Dress codes vary. It is customary in temples in Kerala, for men to remove shirts and to cover pants and shorts with a traditional cloth known as a Vasthiram. In Java and Bali (Indonesia), before one enters the most sacred parts of a Hindu temple, shirts are required as well as Sarong around one's waist. At many other locations, this formality is unnecessary. Regional variations in Hindu temples Nagara Architecture of North Indian temples North Indian temples are referred to as Nagara style of temple architecture. They have sanctum sanctorum where the deity is present, open on one side from where the devotee obtains darśana. There may or may not be many more surrounding corridors, halls, etc. However, there will be space for devotees to go around the temple in clockwise fashion circumambulation. In North Indian temples, the tallest towers are built over the sanctum sanctorum in which the deity is installed. The north India Nagara style of temple designs often deploy fractal-theme, where smaller parts of the temple are themselves images or geometric re-arrangement of the large temple, a concept that later inspired French and Russian architecture such as the matryoshka principle. One difference is the scope and cardinality, where Hindu temple structures deploy this principle in every dimension with garbhgriya as the primary locus, and each pada as well as zones serving as additional centers of loci. This makes a Nagara Hindu temple architecture symbolically a perennial expression of movement and time, of centrifugal growth fused with the idea of unity in everything. Temples in West Bengal In West Bengal, the Bengali terra cotta temple architecture is found. Due to lack of suitable stone in the alluvial soil locally available, the temple makers had to resort to other materials instead of stone. This gave rise to using terracotta as a medium for temple construction. Terracotta exteriors with rich carvings are a unique feature of Bengali temples. The town of Vishnupur in West Bengal is renowned for this type of architecture. There is also a popular style of building known as Navaratna (nine-towered) or Pancharatna (five-towered). An example of