I’ve come across a US project which wants to preserve the acoustics of old buildings. There have been a few projects in Europe doing this, which have concentrated on ancient churches, Roman theatres and concert halls. But in the American project, the places are mostly not photogenic, the attraction is to listen to the sound. This video below of Trans-Allegheny Lunatic Asylum, West Virginia, plays a piece of music through different spaces in the old stone hospital. It is one of the best demonstrates I have heard of how the room acoustics change how music sounds. 
On my travels, I have found that derelict sites often have the best sounds. When I was asked about some of the weirdest places I had visited by the BBC, one of the places I wrote about was a disused water reservoir in Scotland.
If you like the idea of preserving the acoustic past, Acoustic Archives have launched a Kickstarter campaign to do more work like the video of the asylum. Earlier this year, another Kickstarter campaign raised enough money to preserve The Tank, a sixty-foot-tall water tank. Sound artist Bruce Odland who championed the campaign to Save The Tank said, “If sounds were paintings, the Tank would be the Sistine Chapel.”
Do you have any favourite derelict buildings with stunning acoustics? Please comment below.
 The reverberation times quoted on the video are dominated by low frequencies, which is why they are so large.