The Catalina Ballroom is the island's biggest attraction. It sits in the Avalon harbor and begs visitors with its round facade. Yes, it's beautiful. Yes, the tile mosaic of the naked mermaid is iconic. Yes, it's a monument to a time gone by. Yes, you only need to see it once, and really, the tour should have been 15 minutes...at the most. Catalina was, apparently, the place to go on a weekend mini-break back in the 1930's and 40's for Hollywood celebs and non-famous hipsters, but now the island is a party place for oldsters in their boats who call it "The Island." I call it "The Most Boring Place I Can Imagine," but you can decide for yourself. The gift shop at The Casino is nice. They have great postcards and such with retro, art deco designs, and beautiful tile magnets emulating the "Catalina" tile look. Definitely visit since you're there and will virtually have nothing else to do.