Atlantis the lost empire: Religion

Great Temple of Poseidon

With Poseidon's permission, and under the guidance of the ten kings, they built a magnificent city upon the circles of earth surrounding the Hill of Cleito. Atlantean architects used the red, black and white marble of their county to design buildings of dazzling splendor, with the three colors artfully blended or contrasted to attract and please the eye.
On the hill of Cleito they built her a great palace, and this together with the palaces of the ten kings and the temple of Poseidon all blazed with inlays of gold and precious stones.

The principle temple to Poseidon was the wonder of the entire world. The pinnacled roof was so high that clouds drifted around its spires, and it contained an enormous image of Poseidon riding in his chariot attended by sea nymphs and dolphins. The unique beauty of the city, on its circles of land linked by great bridges across the circles of water, was further enhanced by brilliant gardens, groves of flowering trees, and innumerable sparkling fountains.

Religion

Speaking of religion, the Atlanteans do worshiped the Titans with Poseidon as the new supreme deity. Titans were the children of Gaia, Mother Earth and Ouranos, Father Heaven. They reign over the cosmos until the Olympians lead by Zeus defeated them in the Titan War. The Titans listed here some you heard of and others no so much.  THANK GODS for Theoi.com.  Here are some of the Titans.

Kronos (Cronus) is the Titan of Time and the Ages, especially time where regarded as destructive and all-devouring. He is the youngest of the Original Titans and was Gaia's favorite.  He ruled the cosmos during the so-called Golden Age, after castrating and deposing his father Ouranos (the Sky). Kronos is the ex husband of Rhea. He also the Father of the Olympian and more on this child eating bastard later.

Hyperion is the Titan of Light and the East. He is the father of the lights of heaven—Eos the Dawn, Helios the Sun, and Selene the Moon.

Oceanus is the Titan of the great earth-encircling river Okeanos, the font of all the earth's fresh-water: including rivers, wells, springs and rain-clouds. Oceanus is also the Titan who regulated the rising and setting of the heavenly bodies which were believed to emerge and descend into his watery realm at the ends of the earth. 

Atlas is a second-generation Titan. He is Titan of endurance astronomy and the revolution of the heavenly constellations. Atlas was also the General of the Titan Army.  Atlas led the Titans in a rebellion against Zeus and was condemned to bear the heavens upon his shoulders. Before his punishment he was also the Titan who instructed mankind in the art of astronomy, a tool which was used by sailors in navigation and farmers in measuring the seasons. More on him later ;).

Gaia is Mother Earth. She is from whom everything comes, but she is not quite a divinity, because she is Earth. She bore the Titans as well as monsters like the hundred armed giants, and the first Cyclopes. She is the daughter of Chaos or the Creator, and the Mother of All. She is the first and the last, and wanted all of her children to be happy, no matter what. She is primarily spoken of as a Mother of other Gods, rather than having her own myths.