What is the fine-grained topic of the following text: 1800 Larimer – Xcel Energy’s Headquarters (double LEED Platinum), 1400 Lawrence (the large tower just being finished by the Beck Group), 999 17th Street, 1900 16th Street, 1670 Broadway, and many of the other iconic skyscrapers that shimmer in our beautiful skyline. Only return the topic.
Iconic skyscrapers in Denver