[Man of the Old Hope]

I think that we should not assume that there was a temple to Eru Ilúvatar on the heights of Meneltarma. The relevant texts in Akallabêth say simply that there was a "Hallow" upon the heights:

"But in the midst of the land was a mountain tall and steep, and it was named the Meneltarma, the Pillar of Heaven, and upon it was a high place that was hallowed to Eru Ilûvatar, and it was open and unroofed, and no other temple or fane was there in the land of the Númenóreans."

After the Numenoreans develop a fear of death, and labor to discover some means of raising the dead or prolonging life, and fill "all the land with silent tombs", they turn more and more to pleasure and revelry:

"and after the days of Tar-Ancalimon the offering of the first fruits to Eru was neglected, and men went seldom any more to the Hallow upon the heights of Meneltarma in the midst of the land."

When Tar-Míriel the Queen attempts to flee "the mounting wave, green and cold and plumed with foam," the text simply states that "she strove to ascend the steep ways of the Meneltarma to the holy place".

So until Sauron's "surrender" to Ar-Pharazôn and his seduction of the Numenoreans (save the "Elf-friends", the Faithful) into worshipping Melkor as "the Giver of Freedom" in a horrific, human-sacrificing cult through which the supplicants wished to be released from death, Numenor did not have a temple.

In the notes to Athrabeth Finrod ah Andreth ("The Debate of Finrod and Andreth" - from which comes my signature line) in Morgoth's Ring, C. Tolkien introduces the "Tale of Adanel", a story of how Melkor came to Men in the East before their early First Age migration into Beleriand, promising them marvellous riches, abundant food, and dwellings of ease, if they would but worship him as the Giver of Gifts and would build him a "house upon a high place, and call it the House of the Lord." Eventually sickness and weakness came upon the people, fire and water rebelled against them, and the birds and the beasts shunned them. Those fearful of Melkor's anger and power attempted to placate the Giver by offering as human sacrifices those who openly dissented from his cult.

I'm not sure which of these tales precedes the other in time, but I think we can conclude from them that Melkor and his chief servant Sauron demonstrate a twisted, vile, and evil pattern of fear, subjugation, and destruction in their temple-building and their cultus-devising.