Related Clues:

• Tombs
• Yosemite rock features
• Stadium enclosures
• Locations of some secret meetings
• They're over rotundas
• Rotunda tops
• Mosque toppers
• Igloos, essentially
• Arena tops, sometimes
• Horror-flick sets
• Rounded roofs
• Kremlin toppers
• Burial vaults
• Secret places
• Buckminster Fuller structures