Downtown Denver could get a new addition to its skyline: a massive tower.

There’s at least plans filed with the city to build one.

Denver received a permit application Tuesday for a “spiral tower” planned to be 673 feet tall with a supporting building on the first floor, according to the concept plan submitted to the city. It would be located on the surface parking lot between California and Welton streets, next to the Denver Pavilions.

The tower design features a 70-foot sphere that appears to be open-air. It also has a chord-like embellishment that snakes around the structure to create a spiral appearance and is covered in dozens of orbs.

Though it appears to look like an observation tower, the proposal does not state what the building will be used for.

The site plans for 1546 California St. and 1555 Welton St. were submitted by Ephraim LLC., a company tied to Denver real estate firm NAI Shames Makovsky, according to its state filing.

The real estate firm did not respond to a Denver Gazette request for comment.

The tower will be subject to extra scrutiny as it lies in the Downtown Denver Historic District, meaning it will need permission from the Landmark Preservation Commission. The parking lot is behind two historic structures from the early 1900s on 16th Street: the McClintock Building and the Fontius Building.

Those buildings are also owned by companies tied to the real estate firm behind the tower.

The project has already sparked reactions getting likened to the “Eye of Sauron” from the Lord of the Rings by local alt-weekly Westword. Historic Denver CEO John Deffenbaugh told 9News that he was in disbelief when he first saw the proposal.

“When you look at existing viewing towers in other locations, the site is specifically chosen for that viewing tower,” he said. “And the viewing tower exists for a purpose, and I wonder what the purpose is of putting one here.”