Mentioned by Busy Tourist
61 Best & Fun Things To Do Las Vegas (Nevada)
"If you’re wondering what to do in Vegas on a rainy day, consider a trip to the Adventuredome. It’s a gigantic indoor amusement park with everything from roller coasters to bungee jumping stations, so it can provide hours of entertainment regardless of what the weather is like. As a bonus, it’s open 365 days per year, so it’ll always be an option for you and the kids even if you’re visiting Las Vegas in the off-season."