Philadelphia artist Isaiah Zagar turned bottles, bike wheels and ceramic shards into a 3,000-square-foot maze; after a 2004 threat to dismantle it, the community saved it and tickets now frequently sell out

• Spread across more than 3,000 square feet, Philadelphia’s Magic Gardens survived a threat of demolition in 2004 after residents and art supporters joined forces to preserve it.
• The site has since developed into a museum featuring winding passages, tunnels, indoor galleries and a two-level outdoor sculpture garden.