It is so amusing to learn that Shiv is associated with Number 5 in so many ways, maybe one even can't remember in how may ways. And second interesting thing to know about Shiv is that his most places are in southern India, and that is almost all in Tamil Naadu or in its vicinity. The first one related to number 5 is Shiv's own form, let us start with it ---
Shiv is 5-faced. According to Shaiv Aagam, Shiv performs 5 actions - creation, preservation, dissolution, concealing grace and revealing grace. And each of the actions corresponds to a name and form of a Shiv with varying attributes. His Names with Relation to Action Performed, Direction Faced, and Associated Element are given here --
Sadyojaat - Creation. West. Earth.
Vaamdev - Preservation. North. Water.
Aghor -Dissolution/ Rejuvenation. South. Fire
Tatpurush - Concealing Grace. East. Air.
Eeshaan - Revealing Grace. North-east. Ether (Aakaash).
Though bearing each a different name, form, and set of qualities, these are all aspects of a one Supreme Being - Shiv, and are not to be looked upon as different Deities.
Shiv's Main Mantra
Even Shiv's main Mantra is also Panchaakshar (5-letter) Mantra - "Namah Shivaaya". The 5 alphabets of this Mantra - Na, Ma, Shi, Vaa, and Ya; represent his Eeshaan, Tatpurush, Aghor, Vaam Dev, and Sadyojaat named 5 faces.
Shiv has many temples which are also related to number 5 in many ways. Let us start with
(1) Panch Bhoot Ling Temples
These five Ling Temples are base on 5 elements of Nature - Earth, Water, Ether, Air and Fire. They are located at (1)
Ekaambarnaath Temple (at Kaancheepuram, Tamil Naadu - Earth Lingam) - and here the Deity's name is Ekaambareshwar
(2) Kaalaahastee Temple (Near Tirupati, AP - Air Lingam) - and here the Deity's name is Srikaalaahasteeshwar
(2) Chidaambaram Temple (at Chidaambaram, Tamil Naadu - Ether Lingm) - and here the Deity's name is Nataraaj
(3) Arunaachalam Temple (at Tiruvannamalaai, Tamil Naadu - Fire Lingam) - and here the Deity's name is Arunachaleshwar
(5) Thiruvanikkaval Temple (Jambookeshwar at Trichy or Trichanaapallee, Tamil Naadu - Water Lingam) - and here the Deity's name is Jambookeshwar.
(2) Panch Kedaar Temples
These are also 5 and all of the 5 Kedaar Temples are located in Himaalaya, Uttaraakhand
(1) Kedaarnaath or Kedaareshwar
(4) Madhya-maheshwar, and
(3) Panch Sabhaa
These Panch sabhaa are also 5, and they are also located in Tamil Naadu. these are those 5 places where Shiv performed his Taandav Nritya (dance). Panch Sabhaa means 5 Assembly Halls, so Shiv danced in these 5 Halls various Taandav dances
(1) Chidaambaram - Kanak Sabhaa (Golden Assembly Hall) - Here he performed Aanad Taandav.
(2) Thiruvalngaadu - Ratna Sabhaa (Gem Assembly Hall) - Here he performed Oordhwa Taandav
(3) Madurai - Rajat Sabhaa (Silver Assembly Hall) - Here he performed Sandhyaa Taandav
(4) Tirunalvelly - Taamra Sabhaa (Copper Assembly Hall) - Here he performed Muni Taandav
(5) Kutraalam - Chitra Sabhaa (Picture Assembly Hall) - Here he performed here Tri-Pur Taandav
(4) Panch Raam Kshetra
Panch Aram Kshetra are those 5 Kshetra (places) where the Swaayambhoo Ling, which was broken at the time of the killing of Taarakaasur broke in his throat in 5 pieces. are installed. This Swaayambhoo Ling was being carried by Taarakaasur in his throat and Subramanya (Kaarttikeya) killed him. At that time those 5 pieces fell on the Earth on these places --
(1) Draakshaashraam - Draakshaash Raam Swaamee
(2) Samal Kot - Bheem Raam or Kumaar Raam Swaamee
(3) Guneepundee (Bheemvaram) - Som Raam Swaamee
(4) Palakolloo - Ksheer Raam Swaamee
(5) Amaraavatee - Amar Raam Swaamee - this is the foremost place among all. It is believed that here Indra and other Devtaa worshipped Shiv.
(5) Panch Mahaa Kshetra
Last but the least there is Panch Mahaa Kshetra. All of them are related to one or the other legend...
(1) Mahaabaleshwar at Gokarn,
(4) Murudeshwar, and
Thus these five Shiv Kshetra are also associated with number 5.