The phrase "at a tower" is correct and usable in written English.
It can be used to indicate a location or position in relation to a tower, often in contexts involving navigation, architecture, or storytelling.
Example: "We decided to meet at a tower overlooking the valley to enjoy the sunset."
Alternatives: "by a tower" or "near a tower".
Close by and to its north stood the great Tower of Mangana, which was intended to hold the one end of the chain, planned (but probably never actually installed) by Manuel I Komnenos to close off the Bosphorus, the other end being at a tower erected on the island of the modern Maiden's Tower (Kız Kulesi) off Chrysopolis (modern Üsküdar), known as Damalis or Arkla in Byzantine times.
They don't want to look at a tower".
Writer, an American travelling in Europe stops at a tower in Nimes, France.
The agency found that the 53-year-old worker slipped and fell from a beam at a tower construction site.
Interview at the Pentagon with Major Edward Hillding, a jet pilot, who is in… Writer, an American travelling in Europe stops at a tower in Nimes, France.
It records separate images of the music as performed at a tower designed by the artist Ann Hamilton in Geyserville, Calif., a breathtaking space.
A towering look at a towering man, Spielberg's somber, restrained portrait of our 16th president doesn't have the emotional heft of, say, "Schindler's List," but it reveals a filmmaker confident in his one-of-a-kind gifts.
At a towering 182 metres (600 feet), it would be the world's tallest, twice the height of New York's Statue of Liberty.
Mr. Howard interrupted tractor-plowing an onion field to gaze at a towering derrick a few hundred yards away, where another gas well was being drilled.
At a towering 6 foot 4, Mr. Thoubboron has drawn comparisons to a headstrong Clint Eastwood character who does not tolerate dissent.
And it culminates in the ritualistic burning of a huge effigy of a man, which draws thousands into a circle, gazing at a towering inferno against the cold night sky.
