Possible Clues:

• Performing arts, or platforms for them?
• Speaking sites
• Platforms with stirred up orators exuding love
• Soapboxes, at times
• Metro's trains too long for platforms
• Heads off parts for raised platforms
• Upon which Cicero would have held forth cirrostratus clouds
• Spots for lecterns
• Platforms some of Metro's trains used
• Speakers' stages