I'd like to give you just a short glimpse into a project I've been working on (slowly) since 2006 or earlier. Some models you just don't want to rush, and this is one of them.
New York Penn Station once stood in the same spot where Madison Square Garden and Two Penn Plaza now stand in New York City-- the block between 31st and 33rd Streets bordered by 7th and 8th Avenues.
Through some internet sleuthing I was able to locate and download thousands of photos of Penn Station, and even some handy floor plans and elevations, and then translate those things into 3D space using SketchUp.
I am using SketchUp simply to understand the "ghost" of the building better. It is amazing to be able to piece together the demolished walls, the arches and columns, and the vast spaces and feel, definitely, as if I have some understanding of what it was to be in that place. A complement to still photography. But, I'm taking my time.
What's holding me back is the desire to be accurate. As I learn more, I realize what I have done up to now is often inaccurate. I have created and tossed out three generations of models so far. Another problem is, how to balance detail with file size (appearance vs. performance). I'd rather not break it up into pieces. But the actual building was vast-- covering two entire New York City blocks (32nd Street was "absorbed" and became the central axis to the building after the site was razed in the early 20th Century).
These are some screen shots of the latest incarnation of the model. Not much there. But, maybe fun to look at and imagine what once was. Incidentally, this model appears as the icon for my "Golden Age of Rail" collection on the 3D Warehouse right now. For a sense of scale, notice the small dot on the middle left image-- that's a person.
EDIT: Why is it called New York Pennsylvania Station? Well, back in the glory days, Pennsylvania Railroad was one of the powerhouses of rail. All along its lines, the stations were named very often "Pennsylvania Station." That is why there is a Pittsburgh Pennsylvania Station, a Newark Pennsylvania Station, and a New York Pennsylvania Station (although all that remains of the last is its basement).