Back on topic....yeah it is sad when an iconic venue shuts down.
One of the big ones for Austin was the Steamboat, but that closed before I had a chance to even really know much about it.
One that really sucked was Liberty Lunch. I saw a few great shows there, but it got torn down to build a parking garage
Emo's and Antone's (Stevie Ray Vaughan got his start in Antone's) moved to new locations, in some ways the new locations are better than the old.
And, the most recent with a rich history was the Threadgill's Armadillo World Headquarters. Too many legends to name, but Janis Joplin was one of the big ones.
I have also been to a few venues that are on the national register of historic places, like Floore's in San Antonio (Willie Nelson played there often in his early career).