Vaikuntha (Sanskrit वैकुण्ठ, vaikuṇṭha ), Param Padam (‘supreme abode’), or Paramapadam is the home of Vishnu. It is the eternal abode of Narayana or Vishnu or Hari, his consort Lakshmi, and Shesha, upon whom they rest.
Rig Veda (1.22.20) states, Oṃ tad viṣṇoḥ paramam padam sadā paśyanti sūrayaḥ: "All the suras (i.e., the devas) look towards the feet of Lord Vishnu as the Supreme Abode", referring to Vaikuntam and the Supreme Abode. Vaikunta is considered by Vaishnavites to be the ultimate destination of souls who attain moksha or Liberation.
Vaikuntha is known as Paramdhama where liberated souls dwell for eternal period enjoying pure bliss and happiness in company of Supreme Being Lord Narayana. Vaikuntha is beyond the periphery of material universe and hence, can not be perceived or measured by material science and logics.
Ksheera Sagara or Ocean of milk is known to be the topmost realm in the material universe, even higher than Satyaloka where Brahma resides. It is also sometimes known as local Vaikuntha of material universe which is approachable by devas or demigod in order to meet the lord in case of any emergency or disturbance in universal balance. But, the original vaikuntha is beyond the material universe.
Lord Brahma was shown the eternal abode vaikuntha by Narayana at the time of universal creation. In Srimad Bhagavata or Bhagavata Purana, which is considered as essence of vedic knowledge, this event is described as follows :
The Supreme Lord, being thus very much satisfied with the penance of Lord Brahma, was pleased to manifest His personal abode, Vaikuntha, the supreme abode. This transcendental abode of the Lord is adored by all self-realized persons freed from all kinds of miseries and fear of illusory existence. (SB 2.9.9)
In that personal abode of the Lord, the material modes of ignorance and passion do not prevail, nor is there any of their influence in goodness. There is no predominance of the influence of time, so what to speak of the illusory, external energy; it cannot enter that region. Without discrimination, both the demigods and the demons worship the Supreme Lord as devotees. (SB 2.9.10)
The inhabitants of the Vaikuntha planets are described as having a glowing sky-bluish complexion. Their eyes resemble lotus flowers, their dress is of yellowish color, and their bodily features very attractive. They are just the age of growing youths, they all have four hands, they are all nicely decorated with pearl necklaces with ornamental medallions, and they all appear to be effulgent. (SB 2.9.11)
Some of them are effulgent like coral and diamonds in complexion and have garlands on their heads, blooming like lotus flowers, and some wear earrings. (SB 2.9.12)
The Vaikuntha planets are also surrounded by various airplanes, all glowing and brilliantly situated. These airplanes belong to the great mahatmas or devotees of the Lord. The ladies are as beautiful as lightning because of their celestial complexions, and all these combined together appear just like the sky decorated with both clouds and lightning. (SB 2.9.13)
The Goddess of fortune, Lakshmi in her transcendental form is engaged in the loving service of the Lord's lotus feet, and being moved by the black bees, followers of spring, she is not only engaged in variegated pleasure -- service to the Lord, along with her constant companions -- but is also engaged in singing the glories of the Lord's activities. (SB 2.9.14)
Lord Brahma saw in the Vaikuntha, the Supreme Being Narayana, who is the Lord of the entire devotee community, the Lord of the goddess of fortune, the Lord of all sacrifices, and the Lord of the universe, and who is served by the foremost servitors like Nanda, Sunanda, Prabala and Arhana, His immediate associates. (SB 2.9.15)
The Lord, seen leaning favorably towards His loving servitors, His very sight intoxicating and attractive, appeared to be very much satisfied. He had a smiling face decorated with an enchanting reddish hue. He was dressed in yellow robes and wore earrings and a helmet on his head. He had four hands, and His chest was marked with the lines of the goddess of fortune. (SB 2.9.16)
The Lord was seated on His throne and was surrounded by different energies like the four, the sixteen, the five, and the six natural opulences, along with other insignificant energies of the temporary character. But He was the factual Supreme Lord, enjoying His own abode. (SB 2.9.17)