The Sun Theater in Saint Louis was built just prior to WWI in 1913 as the Victoria Theater. It has undergone several name-changes throughout the years, becoming a Jazz club and even an X-rated movie theater, until eventually obtaining its current designation as the Sun. It has been abandoned since its last occupants, the Faith Tabernacle, left in 1981.
Crumbling from the inside out, full of pigeon excrement and overall badly deteriorated, it would be no small feat to restore the interior of the building. It has obviously been horribly neglected for a long time, but considering that the facade of the building is still maintained-to the extent that the sign is still lit up at night, we just weren't expecting it to be so trashed inside. Restoration is a formidable challenge for a building in this state of internal disrepair. Additionally, it is surrounded by some strong competition, most notably the Fox Theater and Powell Symphony Hall, both of which are just around the corner.
Update: The Sun Theater has been completely renovated.