While flying over south Chicago last month, I saw a large roundhouse and turntable. I wonder how many still exist that are in good condition, maybe with working turntables. My guess is a dozen max.
There’s still two roundhouses in the Birmingham, Al area. One is still used on the CSX but doesn’t have a turntable anymore the other is ex Southern and is used by a business. The BNSF (Frisco) has a functional turntable but the roundhouse is gone! They were interesting pieces of our history. It’s a shame more of them weren’t preserved.
About 4 or 5 years ago while in Colorado Springs I saw some gitf shops etc which looked like they were in an old round house. I am not sure about the address I will check it out when I am out there in early july.
Probably not quite the reply you are looking for TBat55 but there is a full circle (52 bay) Roundhouse with a working turntable which is in good condition in Rockhampton, Queensland, Australia. It is curruntly used to house the Railway Workshops office building, the blacksmiths and to store preserved rollingstock and 2 diesel locos.