Vishnu took the form of a Boar.

Brahma and Vishnu were in a fierce cosmic battle about their supremacy. Shiva manifested as an endless pillar of fire to end their arrogance. Stunned by this column of light, Brahma and Vishnu decided to discover its limits.
Vishnu took the form of a boar (Varaha) and descended deep to find the bottom. He returned without success, exhausted but was truthful about his failure. His honesty earned Shiva’s praise and he conferred that Vishnu will have equal status as Shiva among the deities. Brahma lied that he had found the top and was punished by Shiva to be forever without a temple. This episode establishes the worship of Shiva as a Jyotirlinga.
The Wikimedia picture of SSriram is of Shiva as Lingodhbhava with Brahma and Vishnu, from Konerirajapuram temple.
Shiva Purana, J.L Shastri, Chapters 6 & 7

Kankhal is near Haridwar.

Daksha conducted a major Yagna, but did not invite Shiva, his son-in-law. Sati, Daksha’s daughter, nevertheless attended the Yagna. However when Shiva was insulted in the Yagna she immolated herself. This enraged Shiva, and in his grief and anger, he carried her body across the country in a destructive dance. To calm Shiva, Vishnu was requested to intervene. Vishnu gradually dismembered Sati’s body, and these different parts fell at various places, which became known as Shakti Peethas.
Picture by S. R Ramanujam is of Kankhal temple
Kalika Purana, B.N. Shastri, Chapter 16-18

The devas were tormented by Taraka. Only Shiva’s son could kill Taraka but Shiva was not interested in marriage and progeny. At Indra’s request, Kamadeva went with Vasanta and Rati to disturb Shiva’s deep meditation and to make him desire Parvati.
Kama shot his flowery arrow at Shiva. For a moment Shiva was distracted but quickly regained detachment and realised that his penance had been disturbed. From Shiva’s third eye blazed a terrible fire that instantly reduced Kama to ashes.
Eventually Shiva married Parvati. Rati pleaded with Shiva that in the great festival of his marriage, all people are happy. But she alone is unhappy without her husband. Urged by other devas also, Shiva revived Kamadeva.
The 1890 painting is of Shiva burning Kamadeva.
Source. Shiva Purana, J. L Shastri

Indra promised to give all weapons to Arjuna if he first obtains the darshan of Shiva. Arjuna reached the Himalayas and engaged in an extraordinary Tapas. Shiva decided to approach Arjuna as a hunter accompanied by Uma. At the same time, the demon Muka, instigated by Duryodhana, took the form of boar to kill Arjuna. Both Arjuna and Shiva shot an arrow simultaneously which killed Muka. Both claimed that their arrow killed Muka. Arjuna fought Shiva bravely but fell unconscious eventually. Impressed by Arjuna’s bravery, Shiva offered him a boon. Arjuna requested Shiva for Pashupatastra which has terrible powers and can destroy the whole world. Shiva granted the Pashupatastra and taught Arjuna the power to hold, release and also to withdraw the astra. He also told Arjuna how even Indra, Yama, Vayu and Varuna did not know Pashupatastra.
The sculpture from Nanjangud near Mysore depicts this incident. Picture Credit Dineshkannambadi, Wikimedia.
Source: Mahabharata, Vana Parva, Bibek Debroy.

Apasmara represents ignorance. Shiva dancing on Apasmara denotes the eradication of ignorance and the birth of knowledge.
Rishis, enraged by how Shiva as Bhikshatana mesmerized their wives, created four creatures to fight Shiva. Out of these four, Shiva killed the serpent, tiger and the lion. But Shiva could not kill the dwarf Apasmara as the dwarf had unconditional immortality. So Lord Siva brought Apasmara under his control by placing his right foot on Apasmara.
Apasmara means the negation or loss of recollection or consciousness. The unconditional immortality that Apasmara had, also signifies that ignorance is also immortal. Interestingly, in Ayurveda, the word for epilepsy is Apasmara, and it treats epilepsy as a disease of both the body and the mind.
The popular form of Shiva Dakshinamoorthy is the Lord of Knowledge. He also has Apasmara under his gentle feet.
Source: Shiva and Apasmara, Deepa Kiran, Indica Today

The demon Tarakasura had three sons, Tarakaksha, Kamalaksha and Vidyunmali. They obtained a boon from Brahma to dwell in three impregnable, floating cities of iron, silver, and gold. These “Tripuras” could only be destroyed when they are aligned in a single axis once every millennium and are pierced by a single arrow.
The asuras grew arrogant and oppressed the worlds. The devas appealed to Shiva. The cosmos itself transformed into Shiva’s battle-gear: Earth became his chariot, Brahma the charioteer, the Sun and Moon the wheels, and Vishnu the arrow. At the precise moment when the cities were aligned, Shiva merely smiled and shot the three cities with a single arrow, reducing them to ashes. The three cities are also considered as the representation of ego, illusion and impurity.
The picture is 8th Century Western Chalukyan sculpture of Tripurantaka, Picture Credit: Wisdom-Lib
Source: Elements of Hindu Iconography, T.A Gopinath Rao

Banasura, with 1000 hands, was chief among 100 sons of Mahabali (of Onam) and a friend of Narakasura (of Diwali). Shiva, pleased by his devotion, reluctantly granted him the boon that Shiva himself would guard his fort.
Bana’s daughter Usha dreamt of Krishna’s grandson Aniruddha and kidnapped him using mystic powers. Krishna attacked Banasura and Shiva came to protect Bana. Krishna and Shiva had an epic duel. Shiva convinced Krishna to spare Bana, who surrendered. All but four of Bana’s arms were severed and the shedding of so much blood turned the soil red. The place came to be known as Tezpur (Tez – blood) in Assam. Sarahan in Himachal also claims the location of this fight. Usha and Aniruddha were married and came to Dwarka. The Bhagvata Purana tells this story.
The Wikimedia image is Raja Ravi Varma’s painting depicting Usha dreaming of Aniruddha.
Source: pragyata.com

‘Sade Sati’ is a 7.5-year-long, challenging, and transformative period in Vedic astrology when Saturn (Shani) transits through an individual’s natal Moon sign. It is known for bringing karmic lessons and often involves obstacles. Shani is the dispenser of justice for one’s actions – ‘karma-phal-daata.’ Justice moves surely but slowly. ‘Shanischaar’ literally means slow moving, as Saturn takes 30 years to go around the sun.
When it was the turn of Shiva to come under his gaze, Shani pleaded that he cannot exempt Shiva, but will reduce his gaze to a few hours. Shiva decided to escape from the gaze and hid underwater during those hours. Shiva proudly told Shani that he evaded his gaze, but Shani reminded him that Sade Sati makes even Shiva go underwater. This story comes from folklore and has many versions.
The Wikimedia shows Pierre Sonnerat’s 1782 painting of Shanidev.
Source: Bharathkidise.blogspot.com

Kashi ( The Luminous Place) is where the Jyotirlinga (pillar of light) first appeared on earth. It was the place first created by Siva & Shakti. They created the universe from Kashi.
A lesser known story says that Devi Parvati’s parents begin to badger their son-in-law Shiva to find a proper home for his bride. They believed that their daughter deserved a more comfortable home than Kailasha. Siva came to Kashi after having scanned the earth for a lovely place for His family. He vowed never to leave it. He promised to uphold the city on His Trishul even when the rest of universe may submerge in the waters of Pralaya. Shiva makes Kashi, ‘Avimukta’ – which He will never leave.
The image from Navodaya times shows an artist’s imagination of Kashi atop Siva’s Trishul.
Source: “India, A Sacred Geography,” Diana Eck

When Parvati married Siva and came to Kailasha, She found the Ganas didn’t care for grooming, hygiene, and even food. She set up a kitchen but the ganas insisted that they did not need cooked food. Shiva agreed and said that the world does not need Shakti. Parvati left the place in exasperation.
After She left, the world was bereft of energy. Everyone started feeling hungry. After searching the world, the lord found Her in Kashi. He took the form of Vishwanath (God of earth), went to Her and asked for food for His devotees. Devi took the form of Annapoorna and fulfilled the hunger of all people.
This story is puranic. It is also told in ‘Annapoorna Ashtakam’ which also has the mantra often recited before eating, “अन्नपूर्णे सदापूर्णे शङ्करप्राणवल्लभे.” It means “Annapoorna, who is the embodiment of eternal fullness, the one most dear to Shankara.”
The picture shows an Annapoorni temple in the fields of Karsog, Himachal Pradesh. Picture Credit. Ramanujam S. R
Source: Art of Living

Hiranyaksa was killed by Varaha for trying to abduct Prithvi, the earth. Andhakasura was adopted by Hiranyaksa.
Once when Shiva was immersed in yoga, Parvati closed his eyes playfully with her hands, and darkness enveloped the world. Andhaka, meaning ‘from darkness,’ was born from this moment.
Shiva gave the child Andhaka to the Asura king Hiranyaksha to raise as his son. Blessed with a boon, Andhaka became nearly invincible and could be destroyed only if he developed desire for his own mother. After attaining power, he became enamoured of Parvati, unaware of her true relationship to him. Ignoring the counsel of Prahlada, Andhaka advanced against Shiva.
Shiva subdued him with his trident. Humbled by defeat, Andhaka sought forgiveness. Shiva spared his life and accepted him among his ganas, granting him a place as a devoted attendant. This story is prominently told in the Vamana Purana.
The Wikimedia image by Redtigerxyz shows a depiction of Andhakasuramardana at Ellora Caves.
Source: Vettam Mani, ‘Puranic Encyclopedia’, Entry under ‘Andhaka III’

Siva asked Markandeya’s parents “Do you desire to have a virtuous, wise and pious son who would live up to sixteen years or a dull-witted evil-natured son who would live long?” His parents choose the wise son. Markandeya became a genius set to die young. On the intended day of his death, the boy embraced a Shivalinga. Death could not approach Markandeya because of his aura. Therefore Yama threw his rope which encircled both the boy and the linga. An angry Shiva rose from the linga and killed Yama, but revived him later. Shiva thus got the names Mrtyunjaya (conqueror of death), Kalakala (death of death) & Kalantaka (ender of death). Shiva made Markandeya immortal and a great rishi. He is credited with the ‘Ramopkhyana’ (in Mahabharata), the 2nd telling of Ramkatha after Valmiki. He is also credit with the ‘Durga Saptshati’ ( in Markandeya Purana), the key text of Devi worship.
The Wikimedia image is Raja Ravi Varma’s painting of the episode.
Source: Vettam Mani, ‘Puranic Encyclopedia’, Entry under ‘Markandeya’